arXiv daily: Astrophysics of Galaxies

arXiv daily: Astrophysics of Galaxies (astro-ph.GA)

1.Black Hole masses for 14 gravitational lensed quasars

Authors:A. Melo, V. Motta, J. Mejía-Restrepo, R. J. Assef, N. Godoy, E. Mediavilla, E. Falco, C. S. Kochanek, F. Ávila-Vera, R. Jerez

Abstract: We estimate black hole masses (M$_{\rm BH}$) for 14 gravitationally lensed quasars using the Balmer lines along with estimates based on MgII and CIV emission lines for four and two of them, respectively. We compare with results obtained for other lensed quasars. We use spectroscopic data from the Large Binocular Telescope (LBT), Magellan and the Very Large Telescope (VLT) to measure the FWHM of the broad emission lines. Combined with the bolometric luminosity measured from the spectra energy distribution, we estimate M$_{\rm BH}$ including uncertainties from microlensing and variability. We obtain MBH using the single-epoch method from the H$\alpha$ and/or H$\beta$ broad emission lines for 14 lensed quasars, including the first estimates for QJ0158-4325, HE0512-3329 and WFI2026-4536. The masses are typical of non-lensed quasars of similar luminosity, and the implied Eddington ratios are typical. We have increased the sample of lenses with estimates of MBH by 60%.

2.Relativistic phase space diffusion of compact object binaries in stellar clusters and hierarchical triples

Authors:Chris Hamilton, Roman R. Rafikov

Abstract: The LIGO/Virgo detections of compact object mergers have posed a challenge for theories of binary evolution and coalescence. One promising avenue for producing mergers dynamically is through secular eccentricity oscillations driven by an external perturber, be it a tertiary companion (as in the Lidov-Kozai (LK) mechanism) or the tidal field of the stellar cluster in which the binary orbits. The simplest theoretical models of these oscillations use a 'doubly-averaged' (DA) approximation, averaging both over the binary's internal Keplerian orbit and its 'outer' barycentric orbit relative to the perturber. However, DA theories do not account for fluctuations of the perturbing torque on the outer orbital timescale, which are known to increase a binary's eccentricity beyond the maximum DA value, potentially accelerating mergers. Here we reconsider the impact of these short-timescale fluctuations in the test-particle quadrupolar limit for binaries perturbed by arbitrary spherical cluster potentials (including LK as a special case), {in particular including 1pN} general relativistic (GR) apsidal precession of the internal orbit. Focusing on the behavior of the binary orbital elements around peak eccentricity, we discover a new effect, relativistic phase space diffusion (RPSD), in which a binary can jump to a completely new dynamical trajectory on an outer orbital timescale, violating the approximate conservation of DA integrals of motion. RPSD arises from an interplay between secular behavior at extremely high eccentricity, short-timescale fluctuations, and rapid GR precession, and can change the subsequent secular evolution dramatically. This effect occurs even in hierarchical triples, but has not been uncovered until now.

1.Machine Learning and galaxy morphology: for what purpose?

Authors:Didier Fraix-Burnet IPAG

Abstract: Classification of galaxies is traditionally associated with their morphologies through visual inspection of images. The amount of data to come renders this task inhuman and Machine Learning (mainly Deep Learning) has been called to the rescue for more than a decade. However, the results look mitigate and there seems to be a shift away from the paradigm of the traditional morphological classification of galaxies. In this paper, I want to show that the algorithms indeed are very sensitive to the features present in images, features that do not necessarily correspond to the Hubble or de Vaucouleurs vision of a galaxy. However, this does not preclude to get the correct insights into the physics of galaxies. I have applied a state-of-the-art ''traditional'' Machine Learning clustering tool, called Fisher-EM, a latent discriminant subspace Gaussian Mixture Model algorithm, to 4458 galaxies carefully classified into 18 types by the EFIGI project. The optimum number of clusters given by the Integrated Complete Likelihood criterion is 47. The correspondence with the EFIGI classification is correct, but it appears that the Fisher-EM algorithm gives a great importance to the distribution of light which translates to characteristics such as the bulge to disk ratio, the inclination or the presence of foreground stars. The discrimination of some physical parameters (bulge-to-total luminosity ratio, $(B -- B)T$ , intrinsic diameter, presence of flocculence or dust, arm strength) is very comparable in the two classifications.

2.ED-2: a cold but not so narrow stellar stream crossing the Solar neighbourhood

Authors:E. Balbinot, A. Helmi, T. Callingham, T. Matsuno, E. Dodd, T. Ruiz-Lara

Abstract: ED-2 is a stellar stream identified as a compact group in integrals of motion space in a local sample of halo stars from the third Gaia data release. Here we investigate its nature and possible association with known halo substructures. We explore the current properties of ED-2 members in phase-space, and also analyse the expected distribution via orbit integration. In addition, we study the metallicity of ED-2 using APOGEE DR17 and LAMOST DR8 (and re-calibrated DR3). ED-2 forms a compact group in the $x-z$ (or $R-z$) plane, showing a pancake-like structure as it crosses the Solar neighbourhood. Dynamically it is most similar the globular clusters NGC 3201 and NGC 6101, and the stellar stream Ylgr and Phlegethon. However, its orbit is sufficiently different that none of these objects is likely to be ED-2's progenitor. We also find ED-2 to be quite metal-poor, with all of its stars $\mathrm{[Fe/H]} \leq -2.42$, with a median $\mathrm{[Fe/H]} = -2.60^{+0.20}_{-0.21}$. At this low metallicity, it is unlikely that ED-2 stems from any known globular cluster, instead, ED-2 seems to be in a similar category as the recently discovered Phoenix and C-19 stellar streams. We find that ED-2 members are scattered across the whole sky, which is due to its current orbital phase. We predict that as this object moves to its next apocentre it will acquire an on-sky morphology that is akin to cold stellar streams. Finally, since ED-2 is nearing pericentre, we predict that additional members found below the plane should have large radial velocities, close to $\sim$ 500 km/s in the present-day direction of the globular cluster NGC 6101.

3.Measuring Galaxy Asymmetries in 3D

Authors:N. Deg, M. Perron-Cormier, K. Spekkens, M. Glowacki, S. -L. Blyth, N. Hank

Abstract: One of the commonly used non-parametric morphometric statistics for galaxy profiles and images is the asymmetry statistic. With an eye to current and upcoming large neutral hydrogen (HI) surveys, we develop a 3D version of the asymmetry statistic that can be applied to datacubes. This statistic is more resilient to variations due to the observed geometry than 1D asymmetry measures, and can be successfully applied to lower spatial resolutions (3-4 beams across the galaxy major axis) than the 2D statistic. We have also modified the asymmetry definition from an `absolute difference' version to a `squared difference' version that removes much of the bias due to noise contributions for low signal-to-noise observations. Using a suite of mock asymmetric cubes we show that the background-corrected, squared difference 3D asymmetry statistic can be applied to many marginally resolved galaxies in large wide-area HI surveys such as WALLABY on the Australian SKA Pathfinder (ASKAP).

4.Deuterium Fractionation across the Infrared Dark Cloud G034.77-00.55 interacting with the Supernova Remnant W44

Authors:G. Cosentino, J. C. Tan, I. Jiménez-Serra, F. Fontani, P. Caselli, J. D. Henshaw, A. T. Barnes, C. -Y. Law, S. Viti, R. Fedriani, C. -J. Hsu, P. Gorai, S. Zeng

Abstract: Supernova remnants (SNRs) may regulate star formation in galaxies. For example, SNR-driven shocks may form new molecular gas or compress pre-existing clouds and trigger the formation of new stars. To test this scenario, we measure the deuteration of $N_2H^+$, $D_{frac}^{N_2H^+}$, a well-studied tracer of pre-stellar cores, across the Infrared Dark Cloud (IRDC) G034.77-00.55, known to be experiencing a shock interaction with the SNR W44. We use N$_2$H$^+$ and N$_2$D$^+$ J=1-0 single pointing observations obtained with the 30m antenna at the Instituto de Radioastronomia Millimetrica to infer $D_{frac}^{N_2H^+}$ toward five positions across the cloud, namely a massive core, different regions across the shock front, a dense clump and ambient gas. We find $D_{frac}^{N_2H^+}$ in the range 0.03-0.1, several orders of magnitude larger than the cosmic D/H ratio ($\sim$10$^{-5}$). Across the shock front, $D_{frac}^{N_2H^+}$ is enhanced by more than a factor of 2 ($D_{frac}^{N_2H^+}\sim$0.05-0.07) with respect to the ambient gas ($\leq$0.03) and similar to that measured generally in pre-stellar cores. Indeed, in the massive core and dense clump regions of this IRDC we measure $D_{frac}^{N_2H^+}$}$\sim$0.1. We find enhanced deuteration of $N_2H^+$ across the region of the shock, at a level that is enhanced with respect to regions of unperturbed gas. It is possible that this has been induced by shock compression, which would then be indirect evidence that the shock is triggering conditions for future star formation. However, since unperturbed dense regions also show elevated levels of deuteration, further, higher-resolution studies are needed to better understand the structure and kinematics of the deuterated material in the shock region, e.g., if it still in relatively diffuse form or already organised in a population of low-mass pre-stellar cores.

5.The stellar mass of the Gaia-Sausage/Enceladus accretion remnant

Authors:James Lane, Jo Bovy, Ted Mackereth

Abstract: The Gaia-Sausage/Enceladus (GS/E) structure is an accretion remnant in the Milky Way's halo that constitutes a large fraction of the nearby stellar halo. We study GS/E using high-purity samples of kinematically selected stars from APOGEE DR16 and Gaia. Employing a novel modelling framework to account for kinematic selection biases using distribution functions, we fit density profiles to these GS/E samples and measure their masses. We find that GS/E is described by a shallow density profile in the inner Galaxy, with a break between 15-25 kpc beyond which the profile becomes very steep in the outer Galaxy. We also find that GS/E is triaxial, with axis ratios 1:0.55:0.45 (nearly prolate), and the major axis is oriented about 80~degrees from the Sun-Galactic center line and 16 degrees above the plane. We measure a stellar mass for GS/E of $1.45 ^{+0.92}_{-0.51}\,\mathrm{(stat.)}\,^{+0.08}_{-0.49} \mathrm{(sys.)}\ \times10^{8}$ M$_{\odot}$, which is lower than previously estimated. We also fit a density profile to the entire Milky Way stellar halo, finding a mass in the range of $6-8 \times 10^{8}$ M$_{\odot}$, and implying that GS/E could make up as little as 10-20 per cent of the mass of the Milky Way stellar halo. Our findings challenge recent works, which have found greater masses for GS/E, and often find that it dominates the mass budget of the stellar halo. Our lower stellar mass combined with standard stellar-mass-to-halo-mass relations implies that GS/E constituted a minor 1:8-mass-ratio merger at the time of its accretion.

1.FAST polarization mapping of the SNR VRO 42.05.01

Authors:Li Xiao, Ming Zhu, Xiao-Hui Sun, Peng Jiang, Chun Sun

Abstract: We have obtained the polarization data cube of the VRO 42.05.01 supernova remnant at 1240 MHz using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Three-dimensional Faraday Synthesis is applied to the FAST data to derive the Faraday depth spectrum. The peak Faraday depth map shows a large area of enhanced foreground RM of ~60 rad m-2 extending along the remnant's "wing" section, which coincides with a large-scale HI shell at -20 km/s. The two depolarization patches within the "wing" region with RM of 97 rad m-2 and 55 rad m-2 coincide with two HI structures in the HI shell. Faraday screen model fitting on the Canadian Galactic Plane Survey (CGPS) 1420 MHz full-scale polarization data reveals a distance of 0.7-0.8d_{SNR} in front of the SNR with enhanced regular magnetic field there. The highly piled-up magnetic field indicates that the HI shell at -20 km/s could originate from an old evolved SNR.

2.Off-nuclear H$_2$O maser and dense molecular gas in NGC1068

Authors:Yoshiaki Hagiwara, Willem A. Baan, Masatoshi Imanishi, Philip Diamond

Abstract: The results of high-resolution spectral-line observations of dense molecular gas are presented towards the nuclear region of the type 2 Seyfert galaxy NGC1068. MERLIN observations of the 22 GHz H$_2$O maser were made for imaging the known off-nuclear maser emission at radio jet component located about 0.3" north-east of the radio nucleus in the galaxy. High angular resolution ALMA observations have spatially resolved the molecular gas emissions of HCN and HCO$^{+}$ in this region. The off-nuclear maser spots are found to nearly overlap with a ring-like molecular gas structure and are tracing an evolving shock-like structure, which appears to be energized by interaction between the radio jet and circumnuclear medium. A dynamic jet-ISM interaction is further supported by a systematic shift of the centroid velocities of the off-nuclear maser features over a period of 35 years. The integrated flux ratios of the HCO$^{+}$ line emission features at component C suggest a kinetic temperature T$_{k}$ $\gtrsim$ 300K and an H$_2$ density of $\gtrsim$ 10$^6$ cm$^{-3}$, which are conditions where water masers may be formed. The diagnostics of the masering action in this jet-ISM interaction region is exemplary for galaxies hosting off-nuclear H$_2$O maser emission.

3.Halo Scaling Relations and Hydrostatic Mass Bias in the Simba Simulation From Realistic Mock X-ray Catalogues

Authors:Fred Jennings, Romeel Davé

Abstract: We present a new end-to-end pipeline for Mock Observations of X-ray Halos and Analysis (MOXHA) for hydrodynamic simulations of massive halos, and use it to investigate X-ray scaling relations and hydrostatic mass bias in the Simba cosmological hydrodynamic simulation for halos with $M_{500}\sim 10^{13-15}M_\odot$. MOXHA ties together existing yT-based software packages and adds new functionality to provide an end-to-end pipeline for generating mock X-ray halo data from large-scale or zoom simulation boxes. We compare MOXHA-derived halo properties in Simba to their emission-weighted counterparts, and forecast the systematic mass bias in mock Athena observations. Overall, we find inferred hydrostatic masses are biased low compared to true Simba values. For simple mass-weighting, we find $b_\text{MW} = 0.15^{+0.15}_{-0.14}$ ($16-84\%$ range), while emission-weighting increases this to $b_\text{LW}=0.30^{+0.19}_{-0.10}$. The larger bias versus mass-weighted values we attribute to the spectroscopic and emission-weighted temperatures being biased systematically lower than mass-weighted temperatures. The full MOXHA pipeline recovers the emission-weighted hydrostatic masses at $R_{500}$ reasonably well, yielding $b_\text{X}=0.33^{+0.28}_{-0.34}$. MOXHA-derived halo X-ray scalings are in very good agreement with observed scaling relations, with the inclusion of lower-mass groups significantly steepening the $L_\text{X}-M_{500}$, $M_{500}-T_\text{X}$, and $L_\text{X}-T_\text{X}$ relations. This indicates the strong effect the Simba feedback model has on low-mass halos, which strongly evacuates poor groups but still retains enough gas to reproduce observations. We find similar trends for analogous scaling relations measured at $R_{500}$, as expected for halo-wide gas evacuation.

4.Systematically Measuring Ultra-Diffuse Galaxies (SMUDGes). V. The Complete SMUDGes Catalog and the Nature of Ultra-Diffuse Galaxies

Authors:Dennis Zaritsky, Richard Donnerstein, Arjun Dey, Ananthan Karunakaran, Jennifer Kadowaki, Donghyeon J. Khim, Kristine Spekkens, Huanian Zhang

Abstract: We present the completed catalog of ultra-diffuse galaxy (UDG) candidates (7070 objects) from our search of the DR9 Legacy Survey images, including distance and total mass estimates for 1529 and 1436 galaxies, respectively, that we provide and describe in detail. From the sample with estimated distances, we obtain a sample of 585 UDGs ($\mu_{0,g} \ge 24$ mag arcsec$^{-2}$ and $r_e \ge 1.5$ kpc) over 20,000 sq. deg of sky in various environments. We conclude that UDGs in our sample are limited to $10^{10} \lesssim$ M$_h$/M$_\odot \lesssim 10^{11.5}$ and are on average a factor of 1.5 to 7 deficient in stars relative to the general population of galaxies of the same total mass. That factor increases with increasing galaxy size and mass up to a factor of $\sim$10 when the total mass of the UDG increases beyond M$_h = 10^{11}$ M$_\odot$. We do not find evidence that this factor has a dependence on the UDG's large-scale environment.

5.Multiwavelength Bulge-Disk Decomposition for the Galaxy M81 (NGC 3031). I. Morphology

Authors:Ye-Wei Mao, Jun-Yu Gong, Hua Gao, Si-Yue Yu

Abstract: A panchromatic investigation of morphology for the early-type spiral galaxy M81 is presented in this paper. We perform bulge-disk decomposition in M81 images at totally 20 wavebands from FUV to NIR obtained with GALEX, Swift, SDSS, WIYN, 2MASS, WISE, and Spitzer. Morphological parameters such as Sersic index, effective radius, position angle, and axis ratio for the bulge and the disk are thus derived at all the wavebands, which enables quantifying the morphological K-correction for M81 and makes it possible to reproduce images for the bulge and the disk in the galaxy at any waveband. The morphology as a function of wavelength appears as a variable-slope trend of the Sersic index and the effective radius, in which the variations are steep at UV--optical and shallow at optical--NIR bands; the position angle and the axis ratio keep invariable at least at optical--NIR bands. It is worth noting that, the Sersic index for the bulge reaches to about 4--5 at optical and NIR bands, but drops to about 1 at UV bands. This difference brings forward a caveat that, a classical bulge is likely misidentified for a pseudo-bulge or no bulge at high redshifts where galaxies are observed through rest-frame UV channels with optical telescopes. The next work of this series is planned to study spatially resolved SEDs for the bulge and the disk, respectively, and thereby explore stellar population properties and star formation/quenching history for the the galaxy composed of the subsystems.

6.HYPERION. Merger and outflow in the most luminous $z>6$ quasar

Authors:R. Tripodi, J. Scholtz, R. Maiolino, S. Fujimoto, S. Carniani, J. D. Silverman, C. Feruglio, M. Ginolfi, L. Zappacosta, T. Costa, G. C. Jones, E. Piconcelli, M. Bischetti, F. Fiore

Abstract: We present ALMA deep observations of the [CII] 158 $\mu$m emission line and the continuum at 253 GHz and 99 GHz towards SDSS J0100+2802 at $z\simeq 6.3$, the most luminous QSO at z$>$6. It belongs to the HYPERION sample of luminous QSOs at $z\sim 6-7.5$. The observations (at 2.2$''$ resolution in band 3 and 0.9$''$ resolution in band 6) are optimized to detect extended emission around the QSO. We detect a merging, tidally disrupted companion both in [CII] and in continuum, stretching on scales up to 20 kpc from the quasar, with a knotty morphology. For the newly-detected companion we estimate a dust mass of $M_{\rm dust}=(0.6-4.3)\times 10^7\ \rm M_\odot$, an SFR in the range $[43-402]\ \rm M_\odot$, that is remarkably similar to the SFR of the QSO, and a neutral gas mass of $M_{\rm HI}=3.3\times 10^9\ \rm M_{\odot}$, suggesting that both the QSO and its companion are gas rich and that the major merging may be at the origin of the boosted star formation. This close merging companion is undetected by deep JWST imaging observations, supporting the effectiveness of ALMA in detecting dust obscured sources especially in the vicinity of optically bright quasars. We also detect a broad blueshifted component in the [CII] spectrum aligned with the radio jet of the QSO, suggesting that this may be the first detection of a radio jet - driven outflow at such high redshift. We estimate a mass outflow rate in the range $\dot{M}_{\rm out}=(115-269)\ \rm M_\odot\ yr^{-1}$. The outflow energetics is similar to that of ionized outflows found in other QSOs host at lower redshift, and the low momentum loading factor suggests that this outflow would not be very effective in removing the gas from the entire galaxy. These results highlight the importance of deep medium-resolution ALMA observations for the study of QSOs and their environment at the Epoch of Reionization.

7.SOFIA/HAWC+ far-infrared polarimetric large area CMZ exploration (fireplace) survey I: General results from the pilot program

Authors:Natalie O. Butterfield, David T. Chuss, Jordan A. Guerra, Mark R. Morris, Dylan Pare, Edward J. Wollack, C. Darren Dowell, Matthew J. Hankins, Javad Siah, Johannes Staguhn, Ellen Zweibel

Abstract: We present the first data release (DR1) of the Far-Infrared Polarimetric Large Area CMZ Exploration (FIREPLACE) survey. The survey was taken using the 214-micron band of the HAWC+ instrument with the SOFIA telescope (19.6" resolution; 0.7 pc). In this first data release we present dust polarization observations covering a ~0.5degree region of the Galactic Center's Central Molecular Zone (CMZ), centered on the Sgr B2 complex. We detect ~25,000 Nyquist-sampled polarization pseudovectors, after applying the standard SOFIA cuts for minimum signal-to-noise in fractional polarization and total intensity of 3 and 200, respectively. Analysis of the magnetic field orientation suggests a bimodal distribution in the field direction. This bimodal distribution shows enhancements in the distribution of field directions for orientations parallel and perpendicular to the Galactic plane, which is suggestive of a CMZ magnetic field configuration with polodial and torodial components. Furthermore, a detailed analysis of individual clouds included in our survey (i.e., Sgr B2, Sgr B2-NW, Sgr B2-Halo, Sgr B1, and Clouds-E/F) shows these clouds have fractional polarization values of 1-10% at 214-micron, with most of the emission having values <5%. A few of these clouds (i.e., Sgr B2, Clouds-E/F) show relatively low fractional polarization values toward the cores of the cloud, with higher fractional polarization values toward the less dense periphery. We also observe higher fractional polarization towards compact HII regions which could indicate an enhancement in the grain alignment in the dust surrounding these sources.

8.Turbulence in compact to giant H II regions

Authors:J. García-Vázquez ESFM-IPN, Mexico, William J. Henney IRyA-UNAM, Morelia, Mexico, H. O. Castañeda ESFM-IPN, Mexico

Abstract: Radial velocity fluctuations on the plane of the sky are a powerful tool for studying the turbulent dynamics of emission line regions. We conduct a systematic statistical analysis of the H alpha velocity field for a diverse sample of 9 H II regions, spanning two orders of magnitude in size and luminosity, located in the Milky Way and other Local Group galaxies. By fitting a simple model to the second-order spatial structure function of velocity fluctuations, we extract three fundamental parameters: the velocity dispersion, the correlation length, and the power law slope. We determine credibility limits for these parameters in each region, accounting for observational limitations of noise, atmospheric seeing, and the finite map size. The plane-of-sky velocity dispersion is found to be a better diagnostic of turbulent motions than the line width, especially for lower luminosity regions where the turbulence is subsonic. The correlation length of velocity fluctuations is found to be always roughly 2% of the H II region diameter, implying that turbulence is driven on relatively small scales. No evidence is found for any steepening of the structure function in the transition from subsonic to supersonic turbulence, possibly due to the countervailing effect of projection smoothing. Ionized density fluctuations are too large to be explained by the action of the turbulence in any but the highest luminosity sources. A variety of behaviors are seen on scales larger than the correlation length, with only a minority of sources showing evidence for homogeneity on the largest scales.

1.Nobeyama 45-m CO J=1-0 Observations of Luminous Type 1 AGNs at $z\approx0.3$

Authors:Tomonari Michiyama, Ming-Yang Zhuang, Jinyi Shangguan, Hassen M. Yesuf, Hiroyuki Kaneko, Luis C. Ho

Abstract: We have performed CO J =1-0 observations of ten galaxies hosting luminous ($L_{\rm bol} > 10^{46}\,{\rm erg\,s^{-1}}$) type 1 active galactic nuclei (AGNs) with the Nobeyama 45-m radio telescope. The targets are selected because they are expected to be rich in molecular gas based on their high nebular dust extinction ($A_{\rm V}$). However, no significant CO emission lines were detected in any of the targets. The upper limits of the CO J=1-0 luminosities are lower than expected given the molecular gas mass inferred from the nebular $A_{\rm V}$. This inconsistency may be due to overestimated $A_{\rm V}$ values due to the lack of stellar absorption correction. Considering more reliable $A_{\rm V}$ values, the CO J=1-0 non-detections by Nobeyama 45-m are natural. This suggests that our results do not contradict the conversion methods from $A_{\rm V}$ to molecular gas mass proposed in the literature. This survey suggests that careful $A_{\rm V}$ measurements as well as CO observations are still needed to improve the measurements or estimates of the molecular gas content of galaxies hosting luminous AGNs.

2.JWST Measurements of Neutral Hydrogen Fractions and Ionized Bubble Sizes at $z=7-12$ Obtained with Ly$α$ Damping Wing Absorptions in 26 Bright Continuum Galaxies

Authors:Hiroya Umeda, Masami Ouchi, Kimihiko Nakajima, Yuichi Harikane, Yoshiaki Ono, Yi Xu, Yuki Isobe, Yechi Zhang

Abstract: We present volume-averaged neutral hydrogen fractions $x_{\rm \HI}$ and ionized bubble radii $R_{\rm b}$ measured with Ly$\alpha$ damping wing absorptions of galaxies at the epoch of reionization. We combine JWST/NIRSpec spectra taken by CEERS, GO-1433, and DDT-2750 programs, and obtain 26 bright UV-continuum galaxies at $7<z<12$. We construct 4 composite spectra binned by redshift, and find the clear evolution of spectral flattening towards high redshift at the rest-frame $1216$ \AA\ suggesting the increase of Ly$\alpha$ damping wing absorption. We estimate Ly$\alpha$ damping wing absorption in the composite spectra with realistic templates including Ly$\alpha$ emission and circum-galactic medium absorptions. Assuming the standard inside-out reionization picture having an ionized bubble with $R_{\rm b}$ around a galaxy in the inter-galactic medium of $x_{\rm \HI}$, we obtain $x_{\rm \HI}$ ($R_{\rm b}$) values monotonically increasing (decreasing) from $x_{\rm \HI}={0.46}^{+0.36}_{-0.32}$ to ${0.83}^{+0.12}_{-0.21}$ ($R_{\rm b}={1.49}^{+0.37}_{-0.43}\times10^2$ to ${5.04}^{+8.06}_{-3.73}$ comoving Mpc) at redshift $7.140^{+0.039}_{-0.076}$ to $9.801^{+1.599}_{-1.164}$. The redshift evolution of $x_{\rm \HI}$ indicates moderately late reionization history consistent with the one suggested from the electron scattering of cosmic microwave background and the evolution of UV luminosity function with an escape fraction $f_{\rm esc}\simeq 0.17$. Our $R_{\rm b}$ measurements are about 20 times larger than the cosmic average values estimated by analytic calculations for a given $x_{\rm \HI}$, while our $R_{\rm b}$ measurements are comparable with the values for merged ionized bubbles around bright galaxies predicted by recent numerical simulations.

3.Life after AGN switchoff: evolution and properties of fossil galactic outflows

Authors:Kastytis Zubovas, Gediminas Maskeliūnas

Abstract: Galaxy-wide outflows driven by active galactic nuclei (AGN) are an important ingredient in galaxy evolution. Analytical calculations suggest that such outflows have significant inertia and can persist long after the AGN itself fades away. We use hydrodynamical simulations of outflows in idealised galaxy bulges to investigate the propagation of these `fossil' AGN outflows. We find that fossil outflows should be common in gas-poor galaxies but form only rarely in gas-rich ones; in general, fossil outflows should outnumber driven ones by a factor of a few in the local Universe, and possibly more at high redshift. When they do form, fossil outflows tend to be lopsided and detached from the nucleus, and colder than their driven counterparts, with a more prominent molecular phase. Spatially resolved and/or multiphase observations can help distinguish fossil AGN outflows from star formation-driven ones, which have similar integrated properties. We discuss a number of spatially-resolved observations of outflows, suggesting that most show evidence of fossil outflow existence, sometimes together with driven outflows on smaller scales.

4.Underground laboratory JUNA shedding light on stellar nucleosynthesis

Authors:Toshitaka Kajino

Abstract: Extremely low background experiments to measure key nuclear reaction cross sections of astrophysical interest are conducted at the world's deepest underground laboratory, the Jingping Underground laboratory for Nuclear Astrophysics (JUNA). High precision measurements provide reliable information to understand nucleosynthetic processes in celestial objects and resolve mysteries on the origin of atomic nuclei discovered in the first generations of Pop. III stars in the universe and meteoritic SiC grains in the solar system.

5.High resolution modeling of [CII], [CI], [OIII] and CO line emission from the ISM and CGM of a star forming galaxy at z ~ 6.5

Authors:Alice Schimek, Davide Decataldo, Sijing Shen, Claudia Cicone, Bernhard Baumschlager, Eelco van Kampen, Pamela Klaassen, Piero Madau, Luca Di Mascolo, Isabel Montoya Arroyave, Tony Mroczkowski, Jessie Harvir Kaur Warraich

Abstract: The circumgalactic medium (CGM) is a crucial component of galaxy evolution, but thus far its physical properties are highly unconstrained. As of yet, no cosmological simulation has reached convergence when it comes to constraining the cold and dense gas fraction of the CGM. Such components are also challenging to observe, and require sub-millimeter instruments with a high sensitivity to extended, diffuse emission, like the proposed Atacama Large Aperture Sub-millimetre telescope (AtLAST). We present a state-of-the-art theoretical effort at modeling the [CII], [CI](1-0), [CI](2-1), CO(3-2), and [OIII] line emissions of galaxies. We use the high-resolution cosmological zoom-in simulation Ponos, representing a star forming galaxy system at z = 6.5 ($M_*=2\times10^9~M_{\odot}$), undergoing a major merger. We adopt different modeling approaches based on the photoionisation code Cloudy. Our fiducial model uses radiative transfer post-processing with RamsesRT and Krome to create realistic FUV radiation fields, which we compare to sub-grid modeling approaches adopted in the literature. We find significant differences in the luminosity and in the contribution of different gas phases and galaxy components between the different modeling approaches. [CII] is the least model-dependant gas tracer, while [CI](1-0) and CO(3-2) are very model-sensitive. In all models, we find a significant contribution to the emission of [CII] (up to $\sim$10%) and [OIII] (up to $\sim$20%) from the CGM. [CII] and [OIII] trace different regions of the CGM: [CII] arises from an accreting filament and from tidal tails, while [OIII] traces a puffy halo surrounding the main disc, probably linked to SN feedback. We discuss our results in the context of current and future sub-mm observations with ALMA and AtLAST.

6.Extreme damped Lyman-$α$ absorption in young star-forming galaxies at $z=9-11$

Authors:Kasper E. Heintz, Darach Watson, Gabriel Brammer, Simone Vejlgaard, Anne Hutter, Victoria B. Strait, Jorryt Matthee, Pascal A. Oesch, Páll Jakobsson, Nial R. Tanvir, Peter Laursen, Rohan P. Naidu, Charlotte A. Mason, Meghana Killi, Intae Jung, Tiger Yu-Yang Hsiao, Abdurro'uf, Dan Coe, Pablo Arrabal Haro, Steven L. Finkelstein, Sune Toft

Abstract: The onset of galaxy formation is thought to be initiated by the infall of neutral, pristine gas onto the first protogalactic halos. However, direct constraints on the abundance of neutral atomic hydrogen (HI) in galaxies have been difficult to obtain at early cosmic times. Here we present spectroscopic observations with JWST of three galaxies at redshifts $z=8.8 - 11.4$, about $400-600$ Myr after the Big Bang, that show strong damped Lyman-$\alpha$ absorption ($N_{\rm HI} > 10^{22}$ cm$^{-2}$) from HI in their local surroundings, an order of magnitude in excess of the Lyman-$\alpha$ absorption caused by the neutral intergalactic medium at these redshifts. Consequently, these early galaxies cannot be contributing significantly to reionization, at least at their current evolutionary stages. Simulations of galaxy formation show that such massive gas reservoirs surrounding young galaxies so early in the history of the universe is a signature of galaxy formation in progress.

7.Long-term optical spectral monitoring of a changing-look active galactic nucleus NGC 3516 -- II. Broad-line profile variability

Authors:Luka C. Popović, Dragana Ilić, Alexander Burenkov, Victor Manuel Patiño Álvarez, Sladjana Marceta-Mandić, Jelena Kovacević - Dojcinović, Elena Shablovinskaya, Andjelka B. Kovacević, Paola Marziani, Vahram Chavushyan, Jian-Min Wang, Yan-Rong Li, Evencio G. Mediavilla

Abstract: We analyze the broad H$\beta$ line profile variability of the "changing look" active galactic nucleus (CL-AGN) NGC 3516 over a long period of 25 years. The observed change in the broad line profile may indicate a change in the geometry of the broad line region (BLR). Using spectral line profiles, we aim to explore changes in the kinematics and dimensions of the BLR in NGC 3516. We consider two possible scenarios, i.e. changes in the broad-line emission are caused by a decrease of ionization continuum emission or by the BLR obscuration by outer dusty regions. With this investigation we aim to clarify the CL mechanism of this AGN. We analyze the spectral band around the H$\beta$ line as well as the broad H$\beta$ line parameters, and how they change in time. We model the broad-line profiles assuming that there is an emission from the accretion disc superposed with an emission from a surrounding region that is outside the disc. We find that in the Type 1 activity phase, the BLR is very complex. There is a clear disc-like BLR that contributes to the broad line wings and an additional intermediate line region (ILR) that contributes to the line core. In the high activity phase, the ILR emission is close to the center of the line (in some cases slightly shifted to the red), whereas in the low activity phase (i.e., Type 2 phase), the ILR component has a significant shift to the blue, indicating an outflow. We propose that the changing look mechanism in NGC 3516 is rather connected with the intrinsic effects than with an outer obscuring region. It may still be possible that the dust has an important role in the low activity phase when it is coming inside of the BLR, making a dusty BLR. In this way, it causes a decrease in the ionization and recombination rates.

8.Can we really pick and choose? Benchmarking various selections of Gaia Enceladus/Sausage stars in observations with simulations

Authors:Andreia Carrillo, Alis J. Deason, Azadeh Fattahi, Thomas M. Callingham, Robert J. J. Grand

Abstract: Large spectroscopic surveys plus Gaia astrometry have shown us that the inner stellar halo of the Galaxy is dominated by the debris of Gaia Enceladus/Sausage (GES). With the richness of data at hand, there are a myriad of ways these accreted stars have been selected. We investigate these GES selections and their effects on the inferred progenitor properties using data constructed from APOGEE and Gaia. We explore selections made in eccentricity, energy-angular momentum (E-Lz), radial action-angular momentum (Jr-Lz), action diamond, and [Mg/Mn]-[Al/Fe] in the observations, selecting between 144 and 1,279 GES stars with varying contamination from in-situ and other accreted stars. We also use the Auriga cosmological hydrodynamic simulations to benchmark the different GES dynamical selections. Applying the same observational GES cuts to nine Auriga galaxies with a GES, we find that the Jr-Lz method is best for sample purity and the eccentricity method for completeness. Given the average metallicity of GES (-1.28 < [Fe/H] < -1.18), we use the $z=0$ mass-metallicity relationship to find an average $\rm M_{\star}$ of $\sim 4 \times 10^{8}$ $\rm M_{\odot}$. We adopt a similar procedure and derive $\rm M_{\star}$ for the GES-like systems in Auriga and find that the eccentricity method overestimates the true $\rm M_{\star}$ by $\sim2.6\times$ while E-Lz underestimates by $\sim0.7\times$. Lastly, we estimate the total mass of GES to be $\rm 10^{10.5 - 11.1}~M_{\odot}$ using the relationship between the metallicity gradient and the GES-to-in-situ energy ratio. In the end, we cannot just `pick and choose' how we select GES stars, and instead should be motivated by the science question.

9.A quantum-enhanced support vector machine for galaxy classification

Authors:Mohammad Hassan Hassanshahi, Marcin Jastrzebski, Sarah Malik, Ofer Lahav

Abstract: Galaxy morphology, a key tracer of the evolution of a galaxy's physical structure, has motivated extensive research on machine learning techniques for efficient and accurate galaxy classification. The emergence of quantum computers has generated optimism about the potential for significantly improving the accuracy of such classifications by leveraging the large dimensionality of quantum Hilbert space. This paper presents a quantum-enhanced support vector machine algorithm for classifying galaxies based on their morphology. The algorithm requires the computation of a kernel matrix, a task that is performed on a simulated quantum computer using a quantum circuit conjectured to be intractable on classical computers. The result shows similar performance between classical and quantum-enhanced support vector machine algorithms. For a training size of $40$k, the receiver operating characteristic curve for differentiating ellipticals and spirals has an under-curve area (ROC AUC) of $0.946\pm 0.005$ for both classical and quantum-enhanced algorithms. This investigation is among the very first applications of quantum machine learning in astronomy and highlights their potential for further application in this field.

10.One hundred new unidentified optical emission lines from a low-metallicity photodissociation region

Authors:William J. Henney IRyA-UNAM, Morelia, Mexico, Mabel Valerdi INAOE, Puebla, Mexico

Abstract: We report the detection of a rich spectrum of more than one hundred optical emission lines from neutral/molecular gas in the photodissociation region (PDR) around the mini-starburst cluster NGC 346 in the Small Magellanic Cloud. We propose the term Deep Red Line (DRL) for these lines, which are concentrated in the spectral range 6000 Angstrom to 9300 Angstrom and have observed brightnesses ranging from 0.01% to 0.4% times that of the H beta lambda 4861 hydrogen recombination line. The vast majority of the DRLs have never previously been detected from astronomical nebulae. Some of them may be due to neutral atoms, but most have no credible identifications in databases of atomic line transitions, and it is possible that some may correspond to transitions in molecules or molecular ions. Analysis of the spatial distribution of the DRLs shows that they originate from a range of depths in the PDR, providing a missing link between the shallow layers probed by known fluorescent lines of neutral nitrogen and oxygen, and the more shielded layers probed by neutral carbon recombination lines. Comparison with other PDRs shows that the relative strength of the DRLs with respect to the [C I] lambda 8727 line increases rapidly with decreasing metallicity.

11.The origin of the nano-Hertz stochastic gravitational wave background: the contribution from $z\gtrsim1$ supermassive black-hole binaries

Authors:Jean J. Somalwar, Vikram Ravi

Abstract: The nano-Hertz gravitational wave background (GWB) is a key probe of supermassive black hole (SMBH) formation and evolution, if the background arises predominantly from binary SMBHs. The amplitude of the GWB, which is typically quantified in terms of the characteristic strain, $A_{\rm 1 yr}$, at a frequency $1\,{\rm yr}^{-1}$, encodes significant astrophysical information about the SMBH binary (SMBHB) population, including the mass and redshift distributions of SMBHBs. Recent results from a number of pulsar timing arrays have identified a common-spectrum noise process that is consistent with a loud GWB signal with amplitude $A_{\rm 1 yr}{\sim}2\times10^{-15}$, which is higher than typical predictions $A_{\rm 1 yr} \lesssim 10^{-15}$. These predictions usually assume theoretically-motivated but highly uncertain prescriptions for SMBH seeding and evolution. In this work, we use a simple, flexible model of SMBH evolution to explore the possible range of GWB amplitudes, given observational constraints. In particular, we focus on the possible contribution to the GWB from high redshift ($z\gtrsim 1$) SMBHBs, for which few robust observational constraints exist. We find that the GWB amplitude may be higher than fiducial predictions by as much as ${\sim}0.5$ dex if much of the SMBH mass density was established by $z\sim1$. Beyond pulsar timing constraints, observations of the high redshift SMBH population from the James Webb Space Telescope and the Laser Interferometer Space Antenna will be key for constraining the contribution of high-$z$ SMBHBs to the GWB.

12.JWST-JADES. Possible Population III signatures at z=10.6 in the halo of GN-z11

Authors:Roberto Maiolino, Hannah Uebler, Michele Perna, Jan Scholtz, Francesco D'Eugenio, Callum Witten, Nicolas Laporte, Joris Witstok, Stefano Carniani, Sandro Tacchella, William Baker, Santiago Arribas, Kimihiko Nakajima, Daniel Eisenstein, Andrew Bunker, Stephane Charlot, Giovanni Cresci, Mirko Curti, Emma Curtis-Lake, Anna de Graaff, Zhiyuan Ji, Benjamin D. Johnson, Nimisha Kumari, Tobias J. Looser, Michael Maseda, Brant Robertson, Bruno Rodriguez Del Pino, Lester Sandles, Charlotte Simmonds, Renske Smit, Fengwu Sun, Giacomo Venturi, Christina Williams, Christopher Willmer

Abstract: Finding the first generation of stars formed out of pristine gas in the early Universe, known as Population III (PopIII) stars, is one of the most important goals of modern astrophysics. Recent models suggest that PopIII stars may form in pockets of pristine gas in the halo of more evolved galaxies. Here we present NIRSpec-IFU and NIRSpec-MSA observations of the region around GN-z11, an exceptionally luminous galaxy at $z=10.6$, which reveal a $>$5$\sigma$ detection of a feature consistent with being HeII$\lambda$1640 emission at the redshift of GN-z11. The very high equivalent width of the putative HeII emission in this clump (170 A), and the lack of metal lines, can be explained in terms of photoionisation by PopIII stars, while photoionisation by PopII stars is inconsistent with the data. It would also indicate that the putative PopIII stars likely have a top-heavy initial mass function (IMF), with an upper cutoff reaching at least 500 M$_\odot$. The PopIII bolometric luminosity inferred from the HeII line would be $\sim 2\times 10^{10}~L_\odot$, which (with a top-heavy IMF) would imply a total stellar mass formed in the burst of $\sim 6\times 10^{5}~M_\odot$. We find that photoionisation by the Active Galactic Nucleus (AGN) in GN-z11 cannot account for the HeII luminosity observed in the clump, but can potentially be responsible for additional HeII emission observed closer to GN-z11. We also consider the possibility of in-situ photoionisation by an accreting Direct Collapse Black Hole (DCBH) hosted by the HeII clump; we find that this scenario is less favoured, but it remains a possible alternative interpretation. We also report the detection of a Ly$\alpha$ halo stemming out of GN-z11 and extending out to $\sim$2 kpc, as well as resolved, funnel-shaped CIII] emission, likely tracing the ionisation cone of the AGN.

1.A high-resolution spectroscopic analysis of aminoacrylonitrile and an interstellar search towards G+0.693

Authors:D. Alberton, V. Lattanzi, C. Endres, V. M. Rivilla, J. C. Guillemin, P. Caselli, I. Jiménez-Serra, J. Martín-Pintado

Abstract: Cyanides, ranging from three carbon atoms to PAHs, and alkenyl compounds are abundant in the interstellar medium (ISM). Aminoacrylonitrile (3-Amino-2-propenenitrile, H$_{2}$N-CH=CH-CN), an alkenyl cyanide, thus represents a promising candidate for new interstellar detection. A comprehensive spectroscopic laboratory investigation of aminoacrylonitrile in its rotational ground vibrational state has been herein performed. The measurements carried out up to the THz regime made it possible to generate a precise set of reliable rest frequencies for its search in space up to sub-millimetre wavelengths. The $Z$-aminoacrylonitrile ($Z$-apn) isomer spectrum has been recorded employing a source-modulated sub-millimetre spectrometer, from 80 GHz to 1 THz. A combination of Doppler and sub-Doppler measurement regimes allowed to record 600 new lines. The collected data have enabled the characterisation of a set of spectroscopic parameters up to decic centrifugal distortion constants. The catalogue generated from the improved spectral data has been used for the search of $Z$-apn in the spectral survey of the G+0.693-0.027 molecular cloud located in the central molecular zone, in the proximity of the Galactic centre.

2.AFGL 5180 and AFGL 6366S: sites of hub-filament systems at the opposite edges of a filamentary cloud

Authors:A. K. Maity, L. K. Dewangan, N. K. Bhadari, D. K. Ojha, Z. Chen, Rakesh Pandey

Abstract: We present a multi-scale and multi-wavelength study to unveil massive star formation (MSF) processes around sites AFGL 5180, and AFGL 6366S, both hosting a Class II 6.7 GHz methanol maser emission. The radio continuum map at 8.46 GHz reveals a small cluster of radio sources toward AFGL 5180. Signatures of the early stages of MSF in our target sites are spatially seen at the opposite edges of a filamentary cloud (length $\sim$5 pc), which is observed in the sub-millimeter dust continuum maps. Using the near-infrared photometric data, the spatial distribution of young stellar objects is found toward the entire filament, primarily clustered at its edges. The getsf utility on the Herschel far-infrared images reveals a hub-filament system (HFS) toward each target site. The analysis of the molecular line data, which benefits from large area coverage ($\sim$1 degree $\times$ 1 degree), detects two cloud components with a connection in both position and velocity space. This supports the scenario of a cloud-cloud collision (CCC) that occurred $\sim$1 Myr ago. The filamentary cloud, connecting AFGL 5180 and AFGL 6366S, seems spatially close to an HII region Sh2-247 excited by a massive O9.5 star. Based on the knowledge of various pressures exerted by the massive star on its surroundings, the impact of its energetic feedback on the filamentary cloud is found to be insignificant. Overall, our observational outcomes favor the possibility of the CCC scenario driving MSF and the formation of HFSs toward the target sites.

3.Radio continuum tails in ram pressure-stripped spiral galaxies: experimenting with a semi-empirical model in Abell 2255

Authors:A. Ignesti, B. Vulcani, A. Botteon, B. Poggianti, E. Giunchi, R. Smith, G. Brunetti, I. D. Roberts, R. J. van Weeren, K. Rajpurohit

Abstract: Wide-field radio continuum observations of galaxy clusters are revealing an increasing number of spiral galaxies hosting tens of kpc-long radio tails produced by the nonthermal interstellar medium being displaced by the ram pressure. We present a semi-empirical model for the multi-frequency radio continuum emission from ram pressure stripped tails based on the pure synchrotron cooling of a radio plasma moving along the stripping direction with a uniform velocity. We combine LOFAR and uGMRT observations at 144 and 400 MHz to study the flux density and spectral index profiles of the radio tails of 7 galaxies in Abell 2255, and use the model to reproduce the flux density and spectral index profiles, and infer the stripped radio plasma velocity. For 5 out of 7 galaxies we observe monotonic decrease in both flux density and spectral index up to $~30$ kpc from their stellar disk. Our model reproduces the observed trends with a radio plasma bulk projected velocity between 160 and 430 km s$^{-1}$. This result represents the first indirect measure of the stripped, nonthermal interstellar medium velocity. The observed spectral index trends indicate that the synchrotron cooling is faster than the adiabatic expansion losses, thus suggesting that the stripped radio plasma can survive for a few tens of Myr outside of the stellar disk. This provides a lower limit for the lifetime of the stripped ISM outside of the disk. As a proof of concept, we use the best-fit velocities to constrain the galaxies' 3D velocity in the cluster to be in the 300-1300 km s$^{-1}$. We estimate the ram pressure affecting these galaxies to be between 0.1 and 2.9 $\times10^{-11}$ erg cm$^{-3}$, and measure the inclination between their stellar disk and the ram pressure wind.

4.On the fundamentality of the radial acceleration relation for late-type galaxy dynamics

Authors:Richard Stiskalek, Harry Desmond

Abstract: Galaxies have been observed to exhibit a level of simplicity unexpected in the complex galaxy formation scenario posited by standard cosmology. This is particularly apparent in their dynamics, where scaling relations display much regularity and little intrinsic scatter. However, the parameters responsible for this simplicity have not been identified. Using the Spitzer Photometry & Accurate Rotation Curves galaxy catalogue, we argue that the radial acceleration relation (RAR) between galaxies' baryonic and total dynamical accelerations is the fundamental correlation governing the radial (in-disk) dynamics of late-type galaxies. In particular, we show that the RAR cannot be tightened by the inclusion of any other available galaxy property, that it is the strongest projection of galaxies' radial dynamical parameter space, and that all other statistical radial dynamical correlations stem from the RAR plus the non-dynamical correlations present in our sample. We further provide evidence that the RAR's fundamentality is unique in that the second most significant dynamical relation does not possess any of these features. Our analysis reveals the root cause of the correlations present in galaxies' radial dynamics: they are nothing but facets of the RAR. These results have important ramifications for galaxy formation theory because they imply that to explain statistically late-type galaxy dynamics within the disk it is necessary and sufficient to explain the RAR and lack of any significant, partially independent correlation. While simple in some modified dynamics models, this poses a challenge to standard cosmology.

5.Detecting and Characterizing Mg II absorption in DESI Survey Validation Quasar Spectra

Authors:Lucas Napolitano, Agnesh Pandey, Adam D. Myers, Ting-Wen Lan, Abhijeet Anand, Jessica Aguilar, Steven Ahlen, David M. Alexander, David Brooks, Rebecca Canning, Chiara Circosta, Axel De La Macorra, Peter Doel, Sarah Eftekharzadeh, Victoria A. Fawcett, Andreu Font-Ribera, Juan Garcia-Bellido, Satya Gontcho A Gontcho, L. Le Guillou, Julien Guy, Klaus Honscheid, Stephanie Juneau, T. Kisner, Martin Landriau, Aaron M. Meisner, Ramon Miquel, J. Moustakas, Will J. Percival, J. Xavier Prochaska, Michael Schubnell, Gregory Tarle, B. A. Weaver, Benjamin Weiner, Zhimin Zhou, Hu Zou, Siwei Zou

Abstract: In this paper we will present findings on the detection of Magnesium II (MgII, lambda = 2796 {\AA}, 2803 {\AA}) absorption systems observed in data from the Early Data Release (EDR) of the Dark Energy Spectroscopic Instrument (DESI). DESI is projected to obtain spectroscopy of approximately 3 million quasars (QSOs), of which over 99% are anticipated to be found at redshifts greater than z < 0.3, such that DESI would be able to observe an associated or intervening Mg II absorber illuminated by the background QSO. We have developed an autonomous supplementary spectral pipeline that detects such systems through an initial line-fitting process and then confirms line properties using a Markov Chain Monte Carlo (MCMC) sampler. Based upon both a visual inspection and the reanalysis of coadded observations, we estimate this sample of absorption systems to have a completeness of 82.56% and purity of 99.08%. As the spectra in which Mg II systems are detected are the result of coadding multiple observations, we can determine the sensitivity, and therefore completeness, of the sample by searching for known Mg II systems in coadded data with fewer observations (and therefore lower signal-to-noise). From a parent catalog containing 83,207 quasars, we detect a total of 23,921 Mg II absorption systems following a series of quality cuts. Extrapolating from this occurrence rate of 28.75% implies a catalog at the completion of the five-year DESI survey that contains over eight hundred thousand Mg II absorbers. The cataloging of these systems will enable significant further research as they carry information regarding circumgalactic medium (CGM) environments, the distribution of intervening galaxies, and the growth of metallicity across the redshift range 0.3 < z < 2.5.

6.The metallicity dependence of the stellar initial mass function

Authors:Tabassum S. Tanvir, Mark R. Krumholz

Abstract: Dust is important for star formation because it is the crucial component that couples gas to stellar radiation fields, allowing radiation feedback to influence gas fragmentation and thus the stellar initial mass function (IMF). Variations in dust abundance therefore provide a potential avenue by which variation in galaxy metallicity might affect the IMF. In this paper we present a series of radiation-magnetohydrodynamic simulations in which we vary the metallicity and thus the dust abundance from 1% of Solar to 3$\times$ Solar, spanning the range from the lowest metallicity dwarfs to the most metal-rich early-type galaxies found in the local Universe. We design the simulations to keep all dimensionless parameters constant so that the interaction between feedback and star-forming environments of varying surface density and metallicity is the only factor capable of breaking the symmetry between the simulations and modifying the IMF, allowing us to cleanly isolate and understand the effects of each environmental parameter. We find that at a fixed surface density more metal-rich clouds tend to form a slightly more bottom-heavy IMF than metal-poor ones, primarily because in metal-poor gas radiation feedback is able to propagate further, heating somewhat larger volumes of gas. However, shifts in IMF with metallicity at a fixed surface density are much smaller than shifts with surface density at fixed metallicity; metallicity-induced IMF variations are too small to explain the variations in mass-to-light ratio reported in galaxies of different mass and metallicity. We, therefore, conclude that metallicity variations are much less important than variations in surface density in driving changes in the IMF and that the latter rather than the former are most likely responsible for the IMF variations found in early-type galaxies.

1.Amides inventory towards the G+0.693-0.027 molecular cloud

Authors:S. Zeng, V. M. Rivilla, I. Jiménez-Serra, L. Colzi, J. Martín-Pintado, B. Tercero, P. de Vicente, S. Martín, M. A. Requena-Torres

Abstract: Interstellar amides have attracted significant attentions as they are potential precursors for a wide variety of organics essential to life. However, our current understanding of their formation in space is heavily based on observations in star-forming regions and hence the chemical networks lack the constraints on their early origin. In this work, unbiased sensitive spectral surveys with IRAM 30m and Yebes 40m telescopes are used to systematically study a number of amides towards a quiescent Galactic Centre molecular cloud, G+0.693-0.027. We report the first detection of acetamide (CH3C(O)NH2) and trans-N-methylformamide (CH3NHCHO) towards this cloud. In addition, with the wider frequency coverage of the survey, we revisited the detection of formamide (NH2CHO) and urea (carbamide; NH2C(O)NH2), which had been reported previously towards G+0.693-0.027. Our results are compared with those present in the literature including recent laboratory experiments and chemical models. We find constant abundance ratios independently of the evolutionary stages, suggesting that amides related chemistry is triggered in early evolutionary stages of molecular cloud and remain unaffected by the warm-up phase during the star formation process. Although a correlation between more complex amides and NH2CHO have been suggested, alternative formation routes involving other precursors such as acetaldehyde (CH3CHO), methyl isocyanate (CH3NCO) and methylamine (CH3NH2) may also contribute to the production of amides. Observations of amides together with these species towards a larger sample of sources can help to constrain the amide chemistry in the interstellar medium.

1.Galaxy And Mass Assembly (GAMA): Comparing Visually and Spectroscopically Identified Galaxy Merger Samples

Authors:Alice Desmons, Sarah Brough, Cristina Martínez-Lombilla, Roberto De Propris, Benne Holwerda, Ángel R. López Sánchez

Abstract: We conduct a comparison of the merging galaxy populations detected by a sample of visual identification of tidal features around galaxies as well as spectroscopically-detected close pairs of galaxies to determine whether our method of selecting merging galaxies biases our understanding of galaxy interactions. Our volume-limited parent sample consists of 852 galaxies from the Galaxy And Mass Assembly (GAMA) survey in the redshift range $0.04 \leq z \leq 0.20$ and stellar mass range $9.50 \leq$ log$_{10}(M_{\star}/\rm{M}_{\odot})\leq 11.0$. We conduct our comparison using images from the Ultradeep layer of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) to visually-classify galaxies with tidal features and compare these to the galaxies in the GAMA spectroscopic close-pair sample. We identify 198 galaxies possessing tidal features, resulting in a tidal feature fraction $f_{\rm{tidal}}$ = 0.23 $\pm$ 0.02. We also identify 80 galaxies involved in close pairs, resulting in a close pair fraction $f_{\rm{pair}}$ = 0.09 $\pm$ 0.01. Upon comparison of our tidal feature and close pair samples we identify 42 galaxies that are present in both samples, yielding a fraction $f_{\rm{both}}$ = 0.05 $\pm$ 0.01. We find evidence to suggest that the sample of close pairs of galaxies is more likely to detect early-stage mergers, where two separate galaxies are still visible, and the tidal feature sample detects later-stage mergers, where only one galaxy nucleus remains visible. The overlap of the close pair and tidal feature samples likely detect intermediate-stage mergers. Our results are in good agreement with the predictions of cosmological hydrodynamical simulations regarding the populations of merging galaxies detected by close pair and tidal feature samples.

2.Implications of $z>{\sim}12$ JWST galaxies for galaxy formation at high redshift

Authors:Yuxiang Qin, Sreedhar Balu, J. Stuart B. Wyithe

Abstract: Using a semi-analytic galaxy-formation model, we study analogues of 8 recently discovered JWST galaxies at $z>{\sim}12$. We select analogues from a cosmological simulation with a $(311{\rm cMpc})^3$ volume and an effective particle number of $10^{12}$ enabling resolution of every atomic-cooling galaxy at $z{\le}20$. We vary model parameters to reproduce the observed UV luminosity function of $5{<}z{<}13$, aiming for a statistically representative high-redshift galaxy mock catalogue. Using the forward-modelled JWST photometry, we identify analogues from this catalogue and study their properties as well as possible evolutionary paths and local environments. We find faint JWST galaxies ($M_{\rm UV}>{\sim}-19.5$) remain consistent with standard galaxy-formation model and that our fiducial catalogue includes large samples of their analogues. The properties of these analogues broadly agree with conventional SED fitting results, except for having systematically lower redshifts due to the evolving UV luminosity function, and for having higher specific star formation rates as a result of burstier histories in our model. On the other hand, only a handful of bright galaxy analogues can be identified for observed $z{\sim}12$ galaxies. Moreover, in order to reproduce $z>{\sim}16$ JWST galaxy candidates, boosted star-forming efficiencies and reduced feedback regulation are necessary relative to models of lower-redshift populations. This suggests star formation in the first galaxies could differ significantly from their lower-redshift counterparts. We also find that these candidates are subject to low-redshift contamination, which is present in our fiducial results as both the dusty or quiescent galaxies at $z{\sim}5$.

3.The Host Galaxy of FRB 20171020A Revisited

Authors:Karen Lee-Waddell, Clancy W. James, Stuart D. Ryder, Elizabeth K. Mahony, Arash Bahramian, Baerbel S. Koribalski, Pravir Kumar, Lachlan Marnoch, Freya O. North-Hickey, Elaine M. Sadler, Ryan Shannon, Nicolas Tejos, Jessica E. Thorne, Jing Wang, Randall Wayth

Abstract: The putative host galaxy of FRB 20171020A was first identified as ESO 601-G036 in 2018, but as no repeat bursts have been detected, direct confirmation of the host remains elusive. In light of recent developments in the field, we re-examine this host and determine a new association confidence level of 98%. At 37 Mpc, this makes ESO 601-G036 the third closest FRB host galaxy to be identified to date and the closest to host an apparently non-repeating FRB (with an estimated repetition rate limit of < 0.011 bursts per day above 10 erg). Due to its close distance, we are able to perform detailed multi-wavelength analysis on the ESO 601-G036 system. Follow-up observations confirm ESO 601-G036 to be a typical star-forming galaxy with HI and stellar masses of log(M_HI/M_sol) ~ 9.2 and log(M_*/M_sol) = 8.64, and a star formation rate of SFR = 0.09 +/- 0.01 M_sol/yr. We detect, for the first time, a diffuse gaseous tail (log(M_HI/M_sol) ~ 8.3) extending to the south-west that suggests recent interactions, likely with the confirmed nearby companion ESO 601-G037. ESO 601-G037 is a stellar shred located to the south of ESO 601-G036 that has an arc-like morphology, is about an order of magnitude less massive, and has a lower gas metallicity that is indicative of a younger stellar population. The properties of the ESO 601-G036 system indicate an ongoing minor merger event, which is affecting the overall gaseous component of the system and the stars within ESO 601-G037. Such activity is consistent with current FRB progenitor models involving magnetars and the signs of recent interactions in other nearby FRB host galaxies.

4.The BarYon CYCLE Project (ByCycle): Identifying and Localizing MgII Metal Absorbers with Machine Learning

Authors:Roland Szakacs, Céline Péroux, Dylan Nelson, Martin A. Zwaan, Daniel Grün, Simon Weng, Alejandra Y. Fresco, Victoria Bollo, Benedetta Casavecchia

Abstract: The upcoming ByCycle project on the VISTA/4MOST multi-object spectrograph will offer new prospects of using a massive sample of $\sim 1$ million high spectral resolution ($R$ = 20,000) background quasars to map the circumgalactic metal content of foreground galaxies (observed at $R$ = 4000 - 7000), as traced by metal absorption. Such large surveys require specialized analysis methodologies. In the absence of early data, we instead produce synthetic 4MOST high-resolution fibre quasar spectra. To do so, we use the TNG50 cosmological magnetohydrodynamical simulation, combining photo-ionization post-processing and ray tracing, to capture MgII ($\lambda2796$, $\lambda2803$) absorbers. We then use this sample to train a Convolutional Neural Network (CNN) which searches for, and estimates the redshift of, MgII absorbers within these spectra. For a test sample of quasar spectra with uniformly distributed properties ($\lambda_{\rm{MgII,2796}}$, $\rm{EW}_{\rm{MgII,2796}}^{\rm{rest}} = 0.05 - 5.15$ \AA, $\rm{SNR} = 3 - 50$), the algorithm has a robust classification accuracy of 98.6 per cent and a mean wavelength accuracy of 6.9 \AA. For high signal-to-noise spectra ($\rm{SNR > 20}$), the algorithm robustly detects and localizes MgII absorbers down to equivalent widths of $\rm{EW}_{\rm{MgII,2796}}^{\rm{rest}} = 0.05$ \AA. For the lowest SNR spectra ($\rm{SNR=3}$), the CNN reliably recovers and localizes EW$_{\rm{MgII,2796}}^{\rm{rest}}$ $\geq$ 0.75 \AA\, absorbers. This is more than sufficient for subsequent Voigt profile fitting to characterize the detected MgII absorbers. We make the code publicly available through GitHub. Our work provides a proof-of-concept for future analyses of quasar spectra datasets numbering in the millions, soon to be delivered by the next generation of surveys.

5.Large-scale turbulent driving regulates star formation in high-redshift gas-rich galaxies II: Influence of magnetic field and turbulent compressive fraction

Authors:Noé Brucy, Patrick Hennebelle, Tine Colman, Simon Iteanu

Abstract: The observed star formation rate in galaxies is well below what it should be if only gravitational collapse was at play. There is still no consensus on what is the main process responsible for the regulation the star formation rate. It has recently been shown that one candidate to regulate star formation, the feedback from massive stars, is suitable only if the mean column density at the kiloparsec scale is not too high, under $\approx 20 \mathrm{M}_\odot\cdot\mathrm{pc}^{-2}$. On the other-hand, intense large scale turbulent driving could possibly slow down star formation in high density environment to values compatible with observations. In this work we explore the effect of the nature and strength of the turbulent driving, as well as the effect of the magnetic field. We perform a large series of feedback regulated numerical simulations of the interstellar medium (ISM) in which bidimensional large scale turbulent driving is also applied. We determine the driving intensity needed to reproduce the Schmidt-Kennicutt (SK) relation for several gas column densities, magnetization and driving compressibility. We confirm that in the absence of turbulent forcing, and even with substantial magnetic field, the SFR is too high, particularly at high column density, compared to the SK relation. We find that the SFR outcome depends strongly on the initial magnetic field and on the compressibility of the turbulent driving. As a consequence, higher magnetic field in high column density environment may lower the energy necessary to sustain a turbulence sufficiently intense to regulate star formation.

6.Molecular Clouds in the Galactic Plane from $l$ = [59.75$^\circ$, 74.75$^\circ$] and $b$ = [$-$5.25$^\circ$, +5.25$^\circ$]

Authors:Chunxue Li, Hongchi Wang, Yuehui Ma, Lianghao Lin, Yang Su, Chong Li, Yan Sun, Xin Zhou, Ji Yang

Abstract: In this paper we present the distribution of molecular gas in the Milky Way Galactic plane from $l$ = [59.75, 74.75]$^{\circ}$ and $b$ = [${-}$5.25, +5.25]$^{\circ}$, using the MWISP $^{12}$CO/$^{13}$CO/$\rm {C}^{18}{O}$ emission line data. The molecular gas in this region can be mainly attributed to the Local spur, Local arm, Perseus arm, and Outer arm. Statistics of the physical properties of the molecular gas in each arm, such as excitation temperature, optical depth, and column density, are presented. Using the DBSCAN algorithm, we identified 15 extremely distant molecular clouds with kinematic distances of 14.72$-$17.77 kpc and masses of 363$-$520 M$_{\odot}$, which we find could be part of the Outer Scutum-Centaurus (OSC) arm identified by \cite{2011ApJ...734L..24D} and \cite{2015ApJ...798L..27S}. It is also possible that, 12 of these 15 extremely distant molecular clouds constitute an independent structure between the Outer and the OSC arms or a spur. There exist two Gaussian components in the vertical distribution of the molecular gas in the Perseus spiral arm. These two Gaussian components correspond to two giant filaments parallel to the Galactic plane. We find an upward warping of the molecular gas in the Outer spiral arm with a displacement of around 270 pc with respect to the Galactic mid-plane.

7.Deciphering the physical basis of the intermediate-scale instability

Authors:Mohamad Shalaby, Timon Thomas, Christoph Pfrommer, Rouven Lemmerz, Virginia Bresci

Abstract: We study the underlying physics of cosmic-ray (CR) driven instabilities that play a crucial role for CR transport across a wide range of scales, from interstellar to galaxy cluster environments. By examining the linear dispersion relation of CR-driven instabilities in a magnetised electron-ion background plasma, we establish that both, the intermediate and gyroscale instabilities have a resonant origin and show that these resonances can be understood via a simple graphical interpretation. These instabilities destabilise wave modes parallel to the large-scale background magnetic field at significantly distinct scales and with very different phase speeds. Furthermore, we show that approximating the electron-ion background plasma with either magnetohydrodynamics (MHD) or Hall-MHD fails to capture the fastest growing instability in the linear regime, namely the intermediate-scale instability. This finding highlights the importance of accurately characterising the background plasma for resolving the most unstable wave modes. Finally, we discuss the implications of the different phase speeds of unstable modes on particle-wave scattering. Further work is needed to investigate the relative importance of these two instabilities in the non-linear, saturated regime and to develop a physical understanding of the effective CR transport coefficients in large-scale CR hydrodynamics theories.

8.New filamentary remnant radio emission and duty cycle constraints in the radio galaxy NGC 6086

Authors:S. Candini, M. Brienza, A. Bonafede, K. Rajpurohit, N. Biava, M. Murgia, F. Loi, R. J. van Weeren, F. Vazza

Abstract: Radio galaxies are a subclass of active galactic nuclei the supermassive black hole releases energy into the environment via relativistic jets. The jets are not constantly active throughout the life of the host galaxy and alternate between active and quiescent phases. Remnant radio galaxies are detected during a quiescent phase and define a class of unique sources to constrain the AGN duty cycle. We present, a spatially resolved radio analysis of the radio galaxy associated with NGC 6086 and constraints on the spectral age of the diffuse emission to investigate the duty cycle and evolution of the source. We use three new low-frequency, high-sensitivity observations, performed with the Low Frequency Array at 144 MHz and with the upgraded Giant Metrewave Radio Telescope at 400 MHz and 675 MHz. To these, we add two Very Large Array archival observations at 1400 and 4700 MHz. In the new observations, we detect a second pair of larger lobes and three regions with a filamentary morphology. We analyse the spectral index trend in the inner remnant lobes and see systematic steeper values at the lower frequencies compared to the GHz ones. Steeper spectral indices are found in the newly detected outer lobes (up to 2.1), as expected if they trace a previous phase of activity of the AGN. However, the differences between the spectra suggest different dynamical evolution within the intragroup medium during their expansion and/or different magnetic field values. We place constraints on the age of the inner and outer lobes and derive the duty cycle of the source. This results in a total active time of $\sim$39%. The filamentary structures have a steep spectral index ($\sim$1) without any spectral index trend and only one of them shows a steepening in the spectrum. Their origin is not yet clear, but they may have formed due to the compression of the plasma or due to magnetic field substructures.

9.O, Ne, Mg, and Fe abundances in hot X-ray emitting halos of galaxy clusters, groups, and giant early-type galaxies with XMM-Newton RGS spectroscopy

Authors:Kotaro Fukushima, Shogo B. Kobayashi, Kyoko Matsushita

Abstract: Chemical elements in the hot medium permeating early-type galaxies, groups, and clusters make them an excellent laboratory for studying metal enrichment and cycling processes in the largest scales of the Universe. Here, we report the XMM-Newton RGS analysis of 14 early-type galaxies, including the well-known brightest cluster galaxies of Perseus, for instance. The spatial distribution of the O/Fe, Ne/Fe, and Mg/Fe ratios is generally flat at the central 60 arcsecond regions of each object, irrespective of whether or not a central Fe abundance drop has been reported. Common profiles between noble gas and normal metal suggest that the dust depletion process does not work predominantly in these systems. Therefore, observed abundance drops are possibly attributed to other origins, like systematics in the atomic codes. Giant systems of high gas mass-to-luminosity ratio tend to hold a hot gas ($\sim$ 2 keV) yielding the solar N/Fe, O/Fe, Ne/Fe, Mg/Fe, and Ni/Fe ratios. Contrarily, light systems at a subkiloelectronvolt temperature regime, including isolated or group-centered galaxies, generally exhibit super-solar N/Fe, Ni/Fe, Ne/O, and Mg/O ratios. We find that the latest supernova nucleosynthesis models fail to reproduce such a super-solar abundance pattern. Possible systematic uncertainties contributing to these high abundance ratios of cool objects are also discussed in tandem with the crucial role of future X-ray missions.

10.First Light And Reionisation Epoch Simulations (FLARES) XIII: the Lyman-continuum emission of high-redshift galaxies

Authors:Louise T. C. Seeyave, Stephen M. Wilkins, Jussi K. Kuusisto, Christopher C. Lovell, Dimitrios Irodotou, Charlotte Simmonds, Aswin P. Vijayan, Peter A. Thomas, William J. Roper, Conor M. Byrne, Gareth T. Jones, Jack C. Turner, Christopher J. Conselice

Abstract: The history of reionisation is highly dependent on the ionising properties of high-redshift galaxies. It is therefore important to have a solid understanding of how the ionising properties of galaxies are linked to physical and observable quantities. In this paper, we use the First Light and Reionisation Epoch Simulations (FLARES) to study the Lyman-continuum (LyC, i.e. hydrogen-ionising) emission of massive ($M_*>10^8\,\mathrm{M_\odot}$) galaxies at redshifts $z=5-10$. We find that the specific ionising emissivity (i.e. intrinsic ionising emissivity per unit stellar mass) decreases as stellar mass increases, due to the combined effects of increasing age and metallicity. FLARES predicts a median ionising photon production efficiency (i.e. intrinsic ionising emissivity per unit intrinsic far-UV luminosity) of $\log_{10}(\xi_{\rm ion}\rm{/erg^{-1}Hz})=25.40^{+0.16}_{-0.17}$, with values spanning the range $\log_{10}(\xi_{\rm ion}\rm{/erg^{-1}Hz})=25-25.75$. This is within the range of many observational estimates, but below some of the extremes observed. We compare the production efficiency with observable properties, and find a weak negative correlation with the UV-continuum slope, and a positive correlation with the OIII equivalent width. We also consider the dust-attenuated production efficiency (i.e. intrinsic ionising emissivity per unit dust-attenuated far-UV luminosity), and find a median of $\log_{10}(\xi_{\rm ion}\rm{/erg^{-1}Hz})\sim25.5$. Within our sample of $M_*>10^8\,\mathrm{M_\odot}$ galaxies, it is the stellar populations in low mass galaxies that contribute the most to the total ionising emissivity. Active galactic nuclei (AGN) emission accounts for $10-20$ % of the total emissivity at a given redshift, and extends the LyC luminosity function by $\sim0.5$ dex.

11.First Light And Reionisation Epoch Simulations (FLARES) XIV: The Balmer/4000~Å Breaks of Distant Galaxies

Authors:Stephen M. Wilkins, Christopher C. Lovell, Dimitrios Irodotou, Aswin P. Vijayan, Anton Vikaeus, Erik Zackrisson, Joseph Caruana, Elizabeth R. Stanway, Christopher J. Conselice, Louise T. C. Seeyave, William J. Roper, Katherine Chworowsky, Steven L. Finkelstein

Abstract: With the successful launch and commissioning of JWST we are now able to routinely spectroscopically probe the rest-frame optical emission of galaxies at $z>6$ for the first time. Amongst the most useful spectral diagnostics used in the optical is the Balmer/4000~\AA\ break; this is, in principle, a diagnostic of the mean ages of composite stellar populations. However, the Balmer break is also sensitive to the shape of the star formation history, the stellar (and gas) metallicity, the presence of nebular continuum emission, and dust attenuation. In this work we explore the origin of the Balmer/4000~\AA\ break using the SYNTHESIZER synthetic observations package. We then make predictions of the Balmer/4000~\AA\ break using the First Light and Reionisation Epoch Simulations (FLARES) at $5<z<10$. We find that the average break strength weakly correlates with stellar mass and rest-frame far-UV luminosity, but that this is predominantly driven by dust attenuation. We also find that break strength provides a weak diagnostic of the age but performs better as a means to constrain star formation and stellar mass, alongside the UV and optical luminosity, respectively.

12.Nitrogen fractionation in ammonia and its insights on nitrogen chemistry

Authors:Elena Redaelli, Luca Bizzocchi, Paola Caselli, Jaime E. Pineda

Abstract: Context. Observations of $\rm ^{14}N/^{15}N$ in the interstellar medium are becoming more frequent thanks to the increased telescope capabilities. However, interpreting these data is still puzzling. In particular, measurements of $\rm ^{14}N/^{15}N$ in diazenylium revealed high levels of anti-fractionation in cold cores. Aims. Furuya & Aikawa (2018), using astrophysical simulations coupled with a gas-grain chemical code, concluded that the $^{15}$N-depletion in prestellar cores could be inherited from the initial stages, when $\rm ^{14}N^{15}N$ is selectively photodissociated and 15N atoms deplete onto the dust grain, forming ammonia ices. We aim to test this hypothesis. Methods. We targeted three sources (the prestellar core L1544, the protostellar envelope IRAS4A, and the shocked region L1157-B1) with distinct degrees of desorption or sputtering of the ammonia ices. We observed the NH3 isotopologues with the GBT, and we inferred the $\rm ^{14}N/^{15}N$ via a spectral fitting of the observed inversion transitions. Results. $^{15}$NH3(1,1) is detected in L1544 and IRAS4A, whilst only upper limits are deduced in L1157-B1. The NH3 isotopic ratio is significantly lower towards the protostar than at the centre of L1544, where it is consistent with the elemental value. We also present the first spatially resolved map of NH3 nitrogen isotopic ratio towards L1544. Conclusions. Our results are in agreement with the hypothesis that ammonia ices are enriched in $^{15}$N, leading to a decrease of the $\rm ^{14}N/^{15}N$ ratio when the ices are sublimated into the gas phase for instance due to the temperature rise in protostellar envelopes. The ammonia $\rm ^{14}N/^{15}N$ value at the centre of L1544 is a factor of 2 lower than that of N2H+, suggesting that the dominant formation pathway is hydrogenation of N atoms on dust grains, followed by non-thermal desorption.

13.JADES + JEMS: A Detailed Look at the Buildup of Central Stellar Cores and Suppression of Star Formation in Galaxies at Redshifts 3 < z < 4.5

Authors:Zhiyuan Ji, Christina C. Williams, Sandro Tacchella, Katherine A. Suess, William M. Baker, Stacey Alberts, Andrew J. Bunker, Benjamin D. Johnson, Brant Robertson, Fengwu Sun, Daniel J. Eisenstein, Marcia Rieke, Michael V. Maseda, Kevin Hainline, Ryan Hausen, George Rieke, Christopher N. A. Willmer, Eiichi Egami, Irene Shivaei, Stefano Carniani, Stephane Charlot, Jacopo Chevallard, Emma Curtis-Lake, Tobias J. Looser, Roberto Maiolino, Chris Willott, Zuyi Chen, Jakob M. Helton, Jianwei Lyu, Erica Nelson, Rachana Bhatawdekar, Kristan Boyett, Lester Sandles

Abstract: We present a spatially resolved study of stellar populations in 6 galaxies with stellar masses $M_*\sim10^{10}M_\odot$ at $z\sim3.7$ using 14-filter JWST/NIRCam imaging from the JADES and JEMS surveys. The 6 galaxies are visually selected to have clumpy substructures with distinct colors over rest-frame $3600-4100$\r{A}, including a bright dominant stellar core that is close to their stellar-light centroids. With 23-filter photometry from HST to JWST, we measure the stellar-population properties of individual structural components via SED fitting using Prospector. We find that the central stellar cores are $\gtrsim2$ times more massive than the Toomre mass, indicating they may not form via in-situ fragmentation. The stellar cores have stellar ages of $0.4-0.7$ Gyr that are similar to the timescale of clump inward migration due to dynamical friction, suggesting that they likely instead formed through the coalescence of giant stellar clumps. While they have not yet quenched, the 6 galaxies are below the star-forming main sequence by $0.2-0.7$ dex. Within each galaxy, we find that the specific star formation rate is lower in the central stellar core, and the stellar-mass surface density of the core is already similar to quenched galaxies of the same masses and redshifts. Meanwhile, the stellar ages of the cores are either comparable to or younger than the extended, smooth parts of the galaxies. Our findings are consistent with model predictions of the gas-rich compaction scenario for the buildup of galaxies' central regions at high redshifts. We are likely witnessing the coeval formation of dense central cores, along with the onset of galaxy-wide quenching at $z>3$.

1.Insight from JWST/NIRCam into galaxy overdensities around bright Ly$α$ emitters during reionization: implications for ionized bubbles at $z \sim 9$

Authors:Lily Whitler, Daniel P. Stark, Ryan Endsley, Zuyi Chen, Charlotte Mason, Michael W. Topping, Stéphane Charlot

Abstract: Several studies have detected Ly$\alpha$ from bright ($M_{UV}\lesssim-21.5$) galaxies during the early stages of reionization despite the significantly neutral IGM. To explain these detections, it has been suggested that z>7 Ly$\alpha$ emitters (LAEs) inhabit large, physical Mpc (pMpc)-scale ionized regions. However, systematic searches for the overdensities of faint galaxies expected to be powering these ionized bubbles around LAEs have been challenging. Here, we use CEERS NIRCam imaging to investigate the possibility of galaxy overdensities associated with two very UV-bright LAEs at z=8.7 in the EGS field. We design a color selection to identify objects at z=8.4-9.1, selecting 28 candidates (including the one LAE in the footprint, EGSY8p7). We model the SEDs of these objects and infer that all are moderately faint ($-21.2\lesssim M_{UV}\lesssim-19.1$) with stellar masses of $M_* \approx 10^{7.5 - 8.8}$ $M_\odot$. All are efficient ionizing agents ($\xi_{ion}^*\sim10^{25.5-26.0}$ Hz erg$^{-1}$) and are generally morphologically simple with only one compact ($r_e\lesssim140$ to $\sim650$ pc) star-forming component. Of the 27 objects besides EGSY8p7, 13 lie within 5' of EGSY8p7, leading to a $4\times$ overdensity in projection at separations <5' (1.4 pMpc in projection at z=8.7). Separations of 10'-15' (2.7-4.1 projected pMpc) are consistent with an average field. The spatial distribution of our sample may qualitatively suggest a large ($R\geq2$ pMpc) ionized bubble encompassing both LAEs in the field, which is theoretically unexpected but may be possible for a galaxy population four times more numerous than the average to create given moderate escape fractions ($f_{esc}\gtrsim0.15$) over long times ($\gtrsim200$ Myr). Upcoming spectroscopic follow up will enable characterization of the size of any ionized bubble that may exist and the properties of the galaxies powering such a bubble.

2.GMRT H I mapping of mid-infrared bright Blue Compact Dwarf Galaxies W1016+3754 & W2326+0608

Authors:Yogesh Chandola, Chao-Wei Tsai, Di Li, Chandreyee Sengupta, Yin-Zhe Ma, Pei Zuo

Abstract: We present the results from deep 21 cm H I mapping of two nearby blue compact dwarf galaxies (BCDGs), W1016+3754 and W2326+0608, using the Giant Metrewave Radio Telescope (GMRT). These BCDGs are bright in mid-infrared (MIR) data and undergoing active star formation. With the GMRT observations, we investigate the role of cold neutral gas as the fuel resource of the current intensive star formation activity. Star formation in these galaxies is likely to be due to the infall of H I gas triggered by gravitational perturbation from nearby galaxies. The BCDG W2326+0608 and nearby galaxy SDSS J232603.86+060835.8 share a common H I envelope. We find star formation takes place in the high H I column density gas ($\gtrsim 10^{21}$\,cm$^{-2}$) regions for both BCDGs. The recent starburst and infall of metal-free gas have kept the metallicity low for the BCDG W1016+3754. The metallicity for W2326+0608 is higher, possibly due to tidal interaction with the nearby galaxy SDSS J232603.86+060835.8.

3.An end-to-end strategy for recovering a free-form potential from a snapshot of stellar coordinates

Authors:Wassim Tenachi, Rodrigo Ibata, Foivos I. Diakogiannis

Abstract: New large observational surveys such as Gaia are leading us into an era of data abundance, offering unprecedented opportunities to discover new physical laws through the power of machine learning. Here we present an end-to-end strategy for recovering a free-form analytical potential from a mere snapshot of stellar positions and velocities. First we show how auto-differentiation can be used to capture an agnostic map of the gravitational potential and its underlying dark matter distribution in the form of a neural network. However, in the context of physics, neural networks are both a plague and a blessing as they are extremely flexible for modeling physical systems but largely consist in non-interpretable black boxes. Therefore, in addition, we show how a complementary symbolic regression approach can be used to open up this neural network into a physically meaningful expression. We demonstrate our strategy by recovering the potential of a toy isochrone system.

4.Origins of the Evil Eye: M64's Stellar Halo Reveals the Recent Accretion of an SMC-mass Satellite

Authors:Adam Smercina, Eric F. Bell, Paul A. Price, Jeremy Bailin, Julianne J. Dalcanton, Roelof S. de Jong, Richard D'Souza, Katya Gozman, In Sung Jang, Antonela Monachesi, David Nidever, Colin T. Slater

Abstract: M64, often called the "Evil Eye" galaxy, is unique among local galaxies. Beyond its dramatic, dusty nucleus, it also hosts an outer gas disk that counter-rotates relative to its stars. The mass of this outer disk is comparable to the gas content of the Small Magellanic Cloud (SMC), prompting the idea that it was likely accreted in a recent minor merger. Yet, detailed follow-up studies of M64's outer disk have shown no evidence of such an event, leading to other interpretations, such as a "flyby" interaction with the distant diffuse satellite Coma P. We present Subaru Hyper Suprime-Cam observations of M64's stellar halo, which resolve its stellar populations and reveal a spectacular radial shell feature, oriented $\sim$30$^{\circ}$ relative to the major axis and along the rotation axis of the outer gas disk. The shell is $\sim$45 kpc southeast of M64, while a similar but more diffuse plume to the northwest extends to $>$100 kpc. We estimate a stellar mass and metallicity for the southern shell of $M_{\star} {=} 1.80~{\pm}~0.54{\times}10^8~M_{\odot}$ and [M/H] $=$ $-$1.0, respectively, and a similar mass of $1.42~{\pm}~0.71{\times}10^8 M_{\odot}$ for the northern plume. Taking into account the accreted material in M64's inner disk, we estimate a total stellar mass for the progenitor satellite of $M_{\rm \star,prog}~{\simeq}~5{\times}10^8~M_{\odot}$. These results suggest that M64 is in the final stages of a minor merger with a gas-rich satellite strikingly similar to the SMC, in which M64's accreted counter-rotating gas originated, and which is responsible for the formation of its dusty inner star-forming disk.

5.Sizes and mass profiles of candidate massive galaxies discovered by JWST at $7<z<9$: evidence for very early formation of the central $\sim$100 pc of present-day ellipticals

Authors:Josephine F. W. Baggen, Pieter van Dokkum, Ivo Labbe, Gabriel Brammer, Tim B. Miller, Rachel Bezanson, Joel Leja, Bingjie Wang, Katherine E. Withaker, Katherine A. Suess

Abstract: The first JWST data revealed an unexpected population of red galaxies that appear to have redshifts of $z\sim 7-9$ and high masses of $M_*$ $\sim$ 10$^{10}$ M$_{\odot}$ (Labb\'e et al. 2023). Here we fit S\'ersic profiles to the F200W NIRCam images of the 13 massive galaxy candidates of Labb\'e et al., to determine their structural parameters. Satisfactory fits were obtained for nine galaxies. We find that their effective radii are extremely small, ranging from $r_{\rm e}\sim 80$ pc to $r_{\rm e} \sim 300$ pc, with a mean of $\langle r_{\rm e}\rangle \approx 150$ pc. For their apparent stellar masses, the galaxies are smaller than any other galaxy population that has been observed at any other redshift. We use the fits to derive circularized three-dimensional stellar mass profiles of the galaxies, and compare these to the mass profiles of massive quiescent galaxies at $z\sim$2.3 and nearby elliptical galaxies. We find that, despite the high redshift galaxies having $10-20$ times smaller half-light radii, the central stellar densities are comparable to those of their putative descendants at later times. The most straightforward interpretation is that the dense compact inner regions of the most massive ellipticals today were already in place $\sim 600$ Myr after the Big Bang. We caution that the redshifts and masses of the galaxies remain to be confirmed, and that the complex NIRCam point spread function is not yet fully characterized.

6.2mm Observations and the Search for High-Redshift Dusty Star-forming Galaxies

Authors:L. L. Cowie, A. J. Barger, F. E. Bauer

Abstract: Finding high-redshift (z>>4) dusty star-forming galaxies is extremely challenging. It has recently been suggested that millimeter selections may be the best approach, since the negative K-correction makes galaxies at a given far-infrared (FIR) luminosity brighter at z>4 than those at z=2-3. Here we analyze this issue using a deep ALMA 2mm sample obtained by targeting ALMA 870um priors (these priors were the result of targeting SCUBA-2 850um sources) in the GOODS-S. We construct the prior-based 2mm galaxy number counts and compare them with published blank field-based 2mm counts, finding good agreement down to 0.2mJy. Only a fraction of the current 2mm extragalactic background light is resolved, and we estimate what observational depths may be needed to resolve it fully. By complementing the 2mm ALMA data with a deep SCUBA-2 450um sample in the GOODS-S, we exploit the steep gradient with redshift of the 2mm to 450um flux density ratio to estimate redshifts for these galaxies without spectroscopic or robust optical/near-infrared photometric redshifts. Our observations measure galaxies with star formation rates in excess of 250 solar masses per year. For these galaxies, the star formation rate densities fall by a factor of 9 from z=2-3 to z=5-6.

7.The Gas Morphology of Nearby Star-Forming Galaxies

Authors:S. K. Stuber, E. Schinnerer, T. G. Williams, M. Querejeta, S. Meidt, E. Emsellem, A. Barnes, R. S. Klessen, A. K. Leroy, J. Neumann, M. C. Sormani, F. Bigiel, M. Chevance, D. Dale, C. Faesi, S. C. O. Glover, K. Grasha, J. M. D. Kruijssen, D. Liu, H. Pan, J. Pety, F. Pinna, T. Saito, A. Usero, E. J. Watkins

Abstract: The morphology of a galaxy stems from secular and environmental processes during its evolutionary history. Thus galaxy morphologies have been a long used tool to gain insights on galaxy evolution. We visually classify morphologies on cloud-scales based on the molecular gas distribution of a large sample of 79 nearby main-sequence galaxies, using 1'' resolution CO(2-1) ALMA observations taken as part of the PHANGS survey. To do so, we devise a morphology classification scheme for different types of bars, spiral arms (grand-design, flocculent, multi-arm and smooth), rings (central and non-central rings) similar to the well-established optical ones, and further introduce bar lane classes. In general, our cold gas based morphologies agree well with the ones based on stellar light. Both our bars as well as grand-design spiral arms are preferentially found at the higher mass end of our sample. Our gas-based classification indicates a potential for misidentification of unbarred galaxies in the optical when massive star formation is present. Central or nuclear rings are present in a third of the sample with a strong preferences for barred galaxies (59%). As stellar bars are present in 45$\pm$5% of our sample galaxies, we explore the utility of molecular gas as tracer of bar lane properties. We find that more curved bar lanes have a shorter radial extent in molecular gas and reside in galaxies with lower molecular to stellar mass ratios than those with straighter geometries. Galaxies display a wide range of CO morphology, and this work provides a catalogue of morphological features in a representative sample of nearby galaxies.

8.The Araucaria Project: Improving the cosmic distance scale

Authors:The Araucaria Project, :, G. Pietrzyński, W. Gieren, P. Karczmarek, M. Górski, B. Zgirski, P. Wielgórski, L. Breuval, K. Suchomska, A. Gallenne, P. Kervella, G. Hajdu, B. Pilecki, J. Storm, N. Nardetto, R. P. Kudritzki, M. Taormina, F. Bresolin, R. Smolec, W. Narloch, C. Gałan, M. Lewis, R. Chini

Abstract: The book consists of a number of short articles that present achievements of the Araucaria members, collaborators, and friends, in various aspects of distance determinations and related topics. It celebrates the 20-year anniversary of the Araucaria Project, acknowledges the people who worked for its success, and popularises our methods and results among broader readership. This book is a part of a project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 695099.

1.A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) XV. The Halpha luminosity function of the Virgo cluster

Authors:A. Boselli, M. Fossati, P. Cote, J. C. Cuillandre, L. Ferrarese, S. Gwyn, P. Amram, M. Ayromlou, M. Balogh, G. Bellusci, M. Boquien, G. Gavazzi, G. Hensler, A. Longobardi, D. Nelson, A. Pillepich, J. Roediger, R. Sanchez-Jansen, M. Sun, G. Trinchieri

Abstract: We use a complete set of deep narrow-band imaging data for 384 galaxies gathered during the VESTIGE survey to derive the first Halpha luminosity function (LF) of the Virgo cluster within R200. The data allow us to cover the whole dynamic range of the Halpha LF (10^36<LHa<10^42 erg s^-1). After they are corrected for [NII] contamination and dust attenuation, the data are used to derive the SFR function in the range 10^-4<SFR<10 Mo yr^-1. These LF are compared to those derived at other frequencies or using different tracers of star formation in Virgo, in other nearby and high-z clusters, in the field, and to those predicted by the IllustrisTNG cosmological hydrodynamical simulations. The Halpha LF of the Virgo cluster is fairly flat (a=-1.07) in the range 10^38.5<LHa<10^40.5 erg s^-1, and it abruptly decreases at lower luminosities. When compared to those derived for other nearby clusters and for the field, the slope and the characteristic luminosity of the Schechter function change as a function of the dynamical mass of the system, of the temperature of the X-rays gas, and of the dynamical pressure exerted on the interstellar medium of galaxies moving at high velocity within the intracluster medium. All these trends can be explained in a scenario in which the activity of SF is reduced in massive clusters due to their hydrodynamical interaction with the surrounding medium, suggesting once again that ram-pressure stripping is the dominant mechanism affecting galaxy evolution in local clusters of dynamical mass M200>10^14 Mo. The comparison with the IllustrisTNG cosmological hydrodynamical simulations shows a more pronounced decrease at the faint end of the distribution. If Virgo is representative of typical nearby clusters of similar mass, this difference suggests that the stripping process in simulated galaxies in these environments is more efficient than observed.

2.Star-forming environments in smoothed particle magnetohydrodynamics simulations I: Clump extraction and properties

Authors:James Wurster, Connar Rowan

Abstract: What is the nature of a star forming clump? Observations reveal these to be chaotic environments being modified and influenced by many physical processes. However, numerical simulations often define these initial star forming clumps to be idealised objects. In this paper, we define and analyse 109 star forming clumps extracted from our previous low-mass star cluster simulations. To define a clump, we identify all the gas in a simulation that ever becomes bound to or accreted onto a star, then follow the gas backwards in time until it decreases to a critical density. This gas, and its neighbouring gas, is defined as our star forming clump. Our clumps span a mass range of $0.15 \lesssim M/$M$_\odot \lesssim 10.2$, while the density range within each clump spans 2--4 orders of magnitude. The gas density distribution is not smooth, indicating that it is highly structured. The clumps are turbulent, with no coherent rotation. Independent of the initial magnetic field strength of the parent cloud, all clumps yield a similar range of field strengths. The clump magnetic field is ordered, but not reflective of the initial field geometry of the parent cloud. In general, most clump properties have a slight trend with clump mass but are independent of (or only very weakly dependent on) the properties of the parent cloud. We conclude that stars are born from a wide variety of environments and there is not a single universal star forming clump.

3.Constraining intermediate-mass black holes from the stellar disc of SgrA*

Authors:Jean-Baptiste Fouvry, María José Bustamante-Rosell, Aaron Zimmerman

Abstract: Stars evolving around a supermassive black hole see their orbital orientations diffuse efficiently, a process called "vector resonant relaxation". In particular, stars within the same disc, i.e. neighbors in orientations, will slowly diffuse away from one another through this stochastic process. We use jointly (i) detailed kinetic predictions for the efficiency of this dilution and (ii) the recent observation of a stellar disc around SgrA*, the supermassive black hole at the centre of the Milky-Way, to constrain SgrA*'s unobserved stellar cluster. Notably, we investigate quantitatively the impact of a population of intermediate mass black holes on the survivability of the stellar disc.

4.Formation of complex organic molecules on interstellar CO ices? Insights from computational chemistry simulations

Authors:Stefano Ferrero, Cecilia Ceccarelli, Piero Ugliengo, Mariona Sodupe, Albert Rimola

Abstract: Carbon ($^3$P) atom is a reactive species that, according to laboratory experiments and theoretical calculations, condensates with interstellar ice components. This fact is of uttermost importance for the chemistry in the interstellar medium (ISM) because the condensation reaction is barrierless and the subsequent species formed are still reactive given their open-shell character. Carbon condensation on CO-rich ices forms the \ch{C=C=O} ($^3$$\Sigma$$^-$) species, which can be easily hydrogenated twice to form ketene (H$_2$CCO). Ketene is very reactive in terrestrial conditions, usually found as an intermediate hard to be isolated in chemical synthesis laboratories. These characteristics suggest that ketene can be a good candidate to form interstellar complex organic molecules (iCOMs) via a two-step process, i.e., its activation followed by a radical-radical coupling. In this work, reactions between ketene and atomic H, and the OH and NH$_2$ radicals on a CO-rich ice model have been explored by means of quantum chemical calculations complemented by kinetic calculations to evaluate if they are favourable in the ISM. Results indicate that H addition to ketene (helped by tunneling) to form the acetyl radical (CH$_3$CO) is the most preferred path, as the reactions with OH and NH$_2$ possess activation energies ($\geq$ 9kJ/mol) hard to surmount in the ISM conditions, unless external processes provide energy to the system. Thus, acetaldehyde (CH$_3$CHO) and, probably, ethanol (CH$_3$CH$_2$OH) formation via further hydrogenations are the possible unique operating synthetic routes. Moreover, from the computed relatively large binding energies of OH and NH$_2$ on CO ice, slow diffusion is expected, hampering possible radical-radical couplings with CH$_3$CO. The astrophysical implications of these findings are discussed considering the incoming James Webb Space Telescope observations.

5.Constraints on the Faint End of the Galaxy Stellar Mass Function at z ~ 4-8 from Deep JWST Data

Authors:Rafael Navarro-Carrera, Pierluigi Rinaldi, Karina I. Caputi, Edoardo Iani, Vasily Kokorev, Sophie E. van Mierlo

Abstract: We analyze a sample of 3300 galaxies between redshifts z~3.5 and z~8.5 selected from JWST images in the Hubble Ultra Deep Field (HUDF) and UKIDSS Ultra Deep Survey field, including objects with stellar masses as low as ~ 10^8 Msun up to z~8. The depth and wavelength coverage of the JWST data allow us, for the first time, to derive robust stellar masses for such high-z, low stellar-mass galaxies on an individual basis. We compute the galaxy stellar mass function (GSMF), after complementing our sample with ancillary data from CANDELS to constrain the GMSF at high stellar masses (M > M*). Our results show a steepening of the low stellar-mass end slope (a) with redshift, with a = -1.61 (+/-0.05) at z~4 and a = -1.98 (+/-0.14) at z~7. We also observe an evolution of the normalization phi* from z~7 to z~4, with phi*(z~4)/phi*(z~7)= 130 (+210/-50). Our study incorporates a novel method for the estimation of the Eddington bias that takes into account its possible dependence both on stellar mass and redshift, while allowing for skewness in the error distribution. We finally compute the resulting cosmic stellar mass density and find a flatter evolution with redshift than previous studies.

6.Mass models of disk galaxies from gas dynamics

Authors:Federico Lelli INAF - Arcetri Astrophysical Observatory

Abstract: I review methods and techniques to build mass models of disk galaxies from gas dynamics. I focus on two key steps: (1) the derivation of rotation curves using 3D emission-line datacubes from HI, CO, and/or H-alpha observations, and (2) the calculation of the gravitational field from near-infrared images and emission-line maps, tracing the stellar and gas mass distributions, respectively. Mass models of nearby galaxies led to the establishment of the radial acceleration relation (RAR): the observed centripetal acceleration from rotation curves closely correlates with that predicted from the baryonic distribution at each galaxy radius, even when dark matter supposedly dominates the gravitational field. I conclude by discussing the (uncertain) location of Local Group dwarf spheroidal galaxies on the RAR defined by more massive disk galaxies.

7.The MOSDEF-LRIS Survey: Detection of Inflowing Gas Towards Three Star-forming Galaxies at z ~ 2

Authors:Andrew Weldon, Naveen A. Reddy, Michael W. Topping, Alice E. Shapley, Xinnan Du, Sedona H. Price, Ryan L. Sanders, Alison L. Coil, Bahram Mobasher, Mariska Kriek, Brian Siana, Saeed Rezaee

Abstract: We report on the discovery of cool gas inflows towards three star-forming galaxies at $\left<z\right>\sim$ 2.30. Analysis of Keck Low-Resolution Imaging Spectrometer spectroscopy reveals redshifted low-ionisation interstellar (LIS) metal absorption lines with centroid velocities of 60 - 130 km $\rm{s}^{-1}$. These inflows represent some of the most robust detections of inflowing gas into isolated, star-forming galaxies at high redshift. Our analysis suggests that the inflows are due to recycling metal-enriched gas from previous ejections. Comparisons between the galaxies with inflows and a larger parent sample of 131 objects indicate that galaxies with detected inflows may have higher specific star-formation rates (sSFR) and star-formation-rate surface densities. However, when additional galaxies without robustly detected inflows based on centroid velocity but whose LIS absorption line profiles indicate large red-wing velocities are considered, galaxies with inflows do not show unique properties relative to those lacking inflows. Additionally, we calculate the covering fraction of cool inflowing gas as a function of red-wing inflow velocity, finding an enhancement in high sSFR binned galaxies, likely due to an increase in the amount of recycling gas. Together, these results suggest that the low detection rate of galaxies with cool inflows is primarily related to the viewing angle rather than the physical properties of the galaxies.

8.Properties and merger signatures of galaxies hosting LISA coalescing massive black hole binaries

Authors:David Izquierdo-Villalba, Monica Colpi, Marta Volonteri, Daniele Spinoso, Silvia Bonoli, Alberto Sesana

Abstract: The gravitational wave (GW) antenna LISA will detect the signal from coalescing massive black hole binaries (MBHBs) of $\rm 10^4\,{-}\,10^7\, M_{\odot}$, providing clues on their formation and growth along cosmic history. Some of these events will be localized with a precision of several to less than a deg$^2$, enabling the possible identification of their host galaxy. This work explores the properties of the host galaxies of LISA MBHBs below $z\,{\lesssim}\,3$. We generate a simulated lightcone by using the semi-analytical model $\mathrm{\texttt{L-Galaxies}}$ applied on the merger trees of the high-resolution N-body cosmological simulation $\mathrm{\texttt{Millennium-II}}$. The model shows that LISA MBHBs are expected to be found in optically dim ($r\,{>}\,20$), star-forming ($\rm sSFR\,{>}\,10^{-10}\, \rm yr^{-1}$), gas-rich ($f_{\rm gas}\,{>}\,0.6$) and disc-dominated ($\rm B/T\,{<}\,0.7$) \textit{low-mass galaxies} of stellar masses $10^8\,{-}\,10^9 M_{\odot}$. However, these properties are indistinguishable from those of galaxies harboring single massive black holes with comparable mass, making difficult the selection of LISA hosts among the whole population of low-mass galaxies. Motivated by this, we explore the possibility of using merger signatures to select LISA hosts. We find that 40-80% of the galaxies housing LISA MBHBs display merger features related to the interaction which brought the secondary MBH to the galaxy. Despite this, around 60% of dwarf galaxies placed in the surroundings of the LISA hosts will show such kind of features as well, challenging the unequivocal detection of LISA hosts through the search of merger signatures. Consequently, the detection of an electromagnetic transient associated with the MBHB merger will be vital to pinpoint the star-forming dwarf galaxy where these binary systems evolve and coalesce.

9.Mapping the multiphase structure of H I in the Low-Latitude Intermediate-Velocity Arch 1

Authors:Luka Vujeva, Antoine Marchal, Peter G. Martin, Mukesh Taank

Abstract: We have analyzed the thermal and turbulent properties of the Low-Latitude Intermediate-Velocity Arch 1 (LLIV1). This was accomplished using archival H I emission and absorption data from two 21,cm line surveys: GHIGLS at $9.^\prime$4 resolution and DHIGLS at $1^\prime$ resolution. The spectral decomposition code $\tt{ROHSA}$ was used to model the column density of different thermal phases and also to analyze an absorption measurement against the radio source 4C~+66.09. From the latter we found spin temperature $T_{\mathrm{s}} \sim 75$K, cold gas mass fraction $f\sim0.5$, and turbulent sonic Mach number $M_t\sim3.4$. Similar to the absorption line modeling against 4C~+66.09, our best emission line decomposition model has no unstable gas across the whole field of view, suggesting that the thermal condensation and phase transition are not on-going but rather have reached an equilibrium state. The cold phase of LLIV1 appears as a collection of elongated filaments that forms a closed structure within the field decomposed. These substructures follow the orientation of the overall large scale cloud, along the diagonal of the GHIGLS field from north-west to south-east (in Galactic coordinates). The angular power spectrum of the cold phase is slightly shallower than that of the warm phase, quantifying that the cold phases have relatively more structure on small scales. Our spatially resolved map of the cold gas mass fraction in LLIV1 from DHIGLS reveals significant variations spanning the possible range of $f$, with mean and standard deviation 0.33 and 0.19, respectively.

10.Stationary solutions of the Schrödinger-Poisson-Euler system and their stability

Authors:Iván Álvarez-Rios, Francisco S. Guzmán

Abstract: We present the construction of stationary boson-fermion spherically symmetric configurations governed by Newtonian gravity. Bosons are described in the Gross-Pitaevskii regime and fermions are assumed to obey Euler equations for an inviscid fluid with polytropic equation of state. The two components are coupled through the gravitational potential. The families of solutions are parametrized by the central value of the wave function describing the bosons and the central denisty of the fluid. We explore the stability of the solutions using numerical evolutions that solve the time dependent Schr\"odinger-Euler-Poisson system, using the truncation error of the numerical methods as the perturbation. We find that all configurations are stable as long as the polytropic equation of state (EoS) is enforced during the evolution. When the configurations are evolved using the ideal gas EoS they all are unstable that decay into a sort of twin solutions that approach a nearly stationary configuration. We expect these solutions and their evolution serve to test numerical codes that are currently being used in the study of Fuzzy Dark Matter plus baryons.

1.VERTICO VI: Cold-gas asymmetries in Virgo cluster galaxies

Authors:Ian D. Roberts, Toby Brown, Nikki Zabel, Christine D. Wilson, Aeree Chung, Laura C. Parker, Dhruv Bisaria, Alessandro Boselli, Barbara Catinella, Ryan Chown, Luca Cortese, Timothy A. Davis, Sara Ellison, Maria Jesus Jimenez-Donaire, Bumhyun Lee, Rory Smith, Kristine Spekkens, Adam R. H. Stevens, Mallory Thorp, Vincente Villanueva, Adam B. Watts, Charlotte Welker, Hyein Yoon

Abstract: We analyze cold-gas distributions in Virgo cluster galaxies using resolved CO(2-1) (tracing molecular hydrogen, H2) and HI observations from the Virgo Environment Traced In CO (VERTICO) and the VLA Imaging of Virgo in Atomic Gas (VIVA) surveys. From a theoretical perspective, it is expected that environmental processes in clusters will have a stronger influence on diffuse atomic gas compared to the relatively dense molecular gas component, and that these environmental perturbations can compress the cold interstellar medium in cluster galaxies leading to elevated star formation. In this work we observationally test these predictions for star-forming satellite galaxies within the Virgo cluster. We divide our Virgo galaxy sample into HI-normal, HI-tailed, and HI-truncated classes and show, unsurprisingly, that the HI-tailed galaxies have the largest quantitative HI asymmetries. We also compare to a control sample of non-cluster galaxies and find that Virgo galaxies, on average, have HI asymmetries that are 40 +/- 10 per cent larger than the control. There is less separation between control, HI-normal, HI-tailed, and HI-truncated galaxies in terms of H2 asymmetries, and on average, Virgo galaxies have H2 asymmetries that are only marginally (20 +/- 10 per cent) larger than the control sample. We find a weak correlation between HI and H2 asymmetries over our entire sample, but a stronger correlation for those specific galaxies being strongly impacted by environmental perturbations. Finally, we divide the discs of the HI-tailed Virgo galaxies into a leading half and trailing half according to the observed tail direction. We find evidence for excess molecular gas mass on the leading halves of the disc. This excess molecular gas on the leading half is accompanied by an excess in star formation rate such that the depletion time is, on average, unchanged.

2.WALLABY Pilot Survey: HI in the host galaxy of a Fast Radio Burst

Authors:M. Glowacki, K. Lee-Waddell, A. T. Deller, N. Deg, A. C. Gordon, J. A. Grundy, L. Marnoch, A. X. Shen, S. D. Ryder, R. M. Shannon, O. I. Wong, H. Dénes, B. S. Koribalski, C. Murugeshan, J. Rhee, T. Westmeier, S. Bhandari, A. Bosma, B. W. Holwerda, J. X. Prochaska

Abstract: We report on the commensal ASKAP detection of a fast radio burst (FRB), FRB20211127I, and the detection of neutral hydrogen (HI) emission in the FRB host galaxy, WALLABYJ131913-185018 (hereafter W13-18). This collaboration between the CRAFT and WALLABY survey teams marks the fifth, and most distant, FRB host galaxy detected in HI, not including the Milky Way. We find that W13-18 has a HI mass of $M_{\rm HI}$ = 6.5 $\times$ 10$^{9}$ M$_{\odot}$, a HI-to-stellar mass ratio of 2.17, and coincides with a continuum radio source of flux density at 1.4 GHz of 1.3 mJy. The HI global spectrum of W13-18 appears to be asymmetric, albeit the HI observation has a low S/N, and the galaxy itself appears modestly undisturbed. These properties are compared to the early literature of HI emission detected in other FRB hosts to date, where either the HI global spectra were strongly asymmetric, or there were clearly disrupted HI intensity map distributions. W13-18 lacks sufficient S/N to determine whether it is significantly less asymmetric in its HI distribution than previous examples of FRB host galaxies. However, there are no strong signs of a major interaction in the HI or optical image of the host galaxy that would stimulate a burst of star formation and hence the production of putative FRB progenitors related to massive stars and their compact remnants.

3.Gas-phase formation of glycolonitrile in the interstellar medium

Authors:Luis Guerrero-Mendez, Anxo Lema-Saavedra, Elena Jimenez, Antonio Fernandez-Ramos, Emilio Martinez-Nunez

Abstract: Our automated reaction discovery program, AutoMeKin, has been utilized to investigate the formation of glycolonitrile (HOCH$_{2}$CN) in the gas phase under the low temperatures of the interstellar medium (ISM). The feasibility of a proposed pathway depends on the absence of barriers above the energy of reactants and the availability of the suggested precursors in the ISM. Based on these criteria, several radical-radical reactions and a radical-molecule reaction have been identified as viable formation routes in the ISM. Among the radical-radical reactions, OH+CH$_{2}$CN appears to be the most relevant, considering the energy of the radicals and its ability to produce glycolonitrile in a single step. However, our analysis reveals that this reaction produces hydrogen isocyanide (HNC) and formaldehyde (CH$_{2}$O), with rate coefficients ranging from (7.3-11.5)$\times$10$^{-10}$ cm$^3$ molecule$^{-1}$ s$^{-1}$ across the temperature range of 10-150 K. This finding is particularly interesing given the persistently unexplained overabundance of hydrogen isocyanide in the ISM. Among the radical-molecule reactions investigated, the most promising one is OH+CH$_{2}$CNH, which forms glycolonitrile and atomic hydrogen with rate coefficients in the range (0.3-6.6)$\times$10$^{-10}$ cm$^3$ molecule$^{-1}$ s$^{-1}$ within the 10-150 K temperature range. Our calculations indicate that the formation of both hydrogen isocyanide and glycolonitrile is efficient under the harsh conditions of the ISM.

4.Unbiased surveys of dust-enshrouded galaxies using ALMA

Authors:K. Kohno, S. Fujimoto, A. Tsujita, V. Kokorev, G. Brammer, G. E. Magdis, F. Valentino, N. Laporte, Fengwu Sun, E. Egami, F. E. Bauer, A. Guerrero, N. Nagar, K. I. Caputi, G. B. Caminha, J. -B. Jolly, K. K. Knudsen, R. Uematsu, Y. Ueda, M. Oguri, A. Zitrin, M. Ouchi, Y. Ono, J. Gonzalez-Lopez, J. Richard, I. Smail, D. Coe, M. Postman, L. Bradley, A. M. Koekemoer, A. M. Munoz Arancibia, M. Dessauges-Zavadsky, D. Espada, H. Umehata, B. Hatsukade, F. Egusa, K. Shimasaku, K. Matsui-Morokuma, W. -H. Wang, T. Wang, Y. Ao, A. J. Baker, Minju M. Lee, C. del P. Lagos, D. H. Hughes, ALCS collaboration

Abstract: The ALMA lensing cluster survey (ALCS) is a 96-hr large program dedicated to uncovering and characterizing intrinsically faint continuum sources and line emitters with the assistance of gravitational lensing. All 33 cluster fields were selected from HST/Spitzer treasury programs including CLASH, Hubble Frontier Fields, and RELICS, which also have Herschel and Chandra coverages. The total sky area surveyed reaches $\sim$133 arcmin$^2$ down to a depth of $\sim$60 $\mu$Jy beam$^{-1}$ (1$\sigma$) at 1.2 mm, yielding 141 secure blind detections of continuum sources and additional 39 sources aided by priors. We present scientific motivation, survey design, the status of spectroscopy follow-up observations, and number counts down to $\sim$7 $\mu$Jy. Synergies with JWST are also discussed.

5.AGN feedback in action in the molecular gas ring of the Seyfert galaxy NGC7172

Authors:A. Alonso-Herrero, S. Garcia-Burillo, M. Pereira-Santaella, T. Shimizu, F. Combes, E. K. S. Hicks, R. Davies, C. Ramos Almeida, I. Garcia-Bernete, S. F. Hoenig, N. A. Levenson, C. Packham, E. Bellocchi, L. K. Hunt, M. Imanishi, C. Ricci, P. Roche

Abstract: We present new ALMA observations of the CO(3-2) transition and 854micron continuum at 0.06-0.3" resolution, together with new VLT/SINFONI observations of NGC7172. This is a luminous (bolometric luminosity of ~10^44 erg/s) Seyfert galaxy that belongs to the Galaxy Activity, Torus, and Outflow Survey (GATOS). The CO(3-2) observations reveal the presence of a highly inclined cold molecular gas ring with an approximate radius of 3-4"~540-720 pc, which is likely associated with an inner Lindblad resonance of a putative stellar bar. There are noncircular motions in the VLT/SINFONI [SiVI]1.96micron and H2 at 2.12micron, and ALMA CO(3-2) velocity fields. After subtracting the stellar velocity field, we detected [SiVI] blueshifted velocities of a few hundred km/s to the south of the AGN. They trace outflowing ionized gas outside the plane of the galaxy and out to projected distances of ~200 pc. The CO(3-2) position-velocity diagram along the kinematic minor axis displays noncircular motions with observed velocities of up to ~150 km/s. Assuming that these are taking place in the disk of the galaxy, the observed velocity signs imply that the molecular gas ring is not only rotating but also outflowing. We derived an integrated cold molecular gas mass outflow rate of ~40 Msun/yr for the ring. Using the 854micron map, we resolved a 32 pc radius torus with a gas mass of 8x10^5 Msun. These torus properties are similar to other Seyfert galaxies in the GATOS sample. We measured a decreased cold molecular gas concentration in the nuclear-torus region relative to the circumnuclear region when compared to other less luminous Seyfert galaxies. We conclude that the effects of AGN feedback in NGC7172, which are likely caused by the AGN wind and/or the moderate luminosity radio jet, are seen as a large-scale outflowing molecular gas ring and accompanying redistribution of molecular gas in the nuclear regions.

6.The spatial distribution of an aromatic molecule, C6H5CN, in the cold dark cloud TMC-1

Authors:J. Cernicharo, B. Tercero, N. Marcelino, M. Agundez, P. de Vicente

Abstract: We present a highly sensitive 2D line survey of TMC-1 obtained with the Yebes 40m radio telescope in the Q-band (31.13-49.53 GHz). These maps cover a region of 320 arcsec x 320 arcsec centred on the position of the QUIJOTE line survey with a spatial sampling of 20 arcsec. The region covering 240 arcsec x 240 arcsec, where a longer integration time was used, shows a homogenous sensitivity of 2-4 mK across the band. We present in this work the first determination of the spatial extent of benzonitrile (C6H5CN), which follows that of cyanopolyynes rather well, but differs significantly from that of the radicals CnH and CnN. We definitively conclude that aromatic species in TMC-1 are formed from chemical reactions involving smaller species in the densest zones of the cloud.

7.Large-scale excess HI absorption around $z\approx4$ galaxies detected in a background galaxy spectrum in the MUSE eXtremely Deep Field

Authors:Jorryt Matthee, Christopher Golling, Ruari Mackenzie, Gabriele Pezzulli, Simon Lilly, Joop Schaye, Roland Bacon, Haruka Kusakabe, Tanya Urrutia, Leindert Boogaard, Jarle Brinchmann, Michael V. Maseda, Thibault Garel, Nicolas F. Bouché, Lutz Wisotzki

Abstract: Observationally mapping the relation between galaxies and the intergalactic medium (IGM) is of key interest for studies of cosmic reionization. Diffuse hydrogen gas has typically been observed in HI Lyman-$\alpha$ (Ly$\alpha$) absorption in the spectra of bright background quasars. However, it is important to extend these measurements to background galaxies as quasars become increasingly rare at high redshift and rarely probe closely separated sight-lines. Here we use deep integral field spectroscopy in the MUSE eXtremely Deep Field to demonstrate the measurement of the Ly$\alpha$ transmission at $z\approx4$ in absorption to a background galaxy at $z=4.77$. The HI transmission is consistent with independent quasar sight-lines at similar redshifts. Exploiting the high number of spectroscopic redshifts of faint galaxies (500 between $z=4.0-4.7$ within a radius of 8 arcmin) that are tracers of the density field, we show that Ly$\alpha$ transmission is inversely correlated with galaxy density, i.e. transparent regions in the Ly$\alpha$ forest mark under-dense regions at $z\approx4$. Due to large-scale clustering, galaxies are surrounded by excess HI absorption over the cosmic mean out to 4 cMpc/h. We also find that redshifts from the peak of the Ly$\alpha$ line are typically offset from the systemic redshift by +170 km/s. This work extends results from $z\approx 2 - 3$ to higher redshifts and demonstrates the power of deep integral field spectroscopy to simultaneously measure the ionization structure of the IGM and the large-scale density field in the early Universe.

8.Modeling the chemical enrichment history of the Bulge Fossil Fragment Terzan 5

Authors:Donatella Romano, Francesco R. Ferraro, Livia Origlia, Simon Portegies Zwart, Barbara Lanzoni, Chiara Crociati, Davide Massari, Emanuele Dalessandro, Alessio Mucciarelli, R. Michael Rich, Francesco Calura, Francesca Matteucci

Abstract: Terzan 5 is a heavily obscured stellar system located in the inner Galaxy. It has been postulated to be a stellar relic, a Bulge Fossil Fragment witnessing the complex history of the assembly of the Milky Way bulge. In this paper, we follow the chemical enrichment of a set of putative progenitors of Terzan 5 to assess whether the chemical properties of this cluster fit within a formation scenario in which it is the remnant of a primordial building block of the bulge. We can explain the metallicity distribution function and the runs of different element-to-iron abundance ratios as functions of [Fe/H] derived from optical-infrared spectroscopy of giant stars in Terzan 5, by assuming that the cluster experienced two major star formation bursts separated by a long quiescent phase. We further predict that the most metal-rich stars in Terzan 5 are moderately He-enhanced and a large spread of He abundances in the cluster, Y = 0.26-0.335. We conclude that current observations fit within a formation scenario in which Terzan 5 originated from a pristine, or slightly metal-enriched, gas clump about one order of magnitude more massive than its present-day mass. Losses of gas and stars played a major role in shaping Terzan 5 the way we see it now. The iron content of the youngest stellar population is better explained if the white dwarfs that give rise to type Ia supernovae (the main Fe factories) sink towards the cluster center, rather than being stripped by the strong tidal forces exerted by the Milky Way in the outer regions.

1.Assessing Mass Loss and Stellar-to-Halo Mass Ratio of Satellite Galaxies: A Galaxy-Galaxy Lensing Approach Utilizing DECaLS DR8 Data

Authors:Chunxiang Wang, Ran Li, Huanyuan Shan, Weiwei Xu, Ji Yao, Yingjie Jing, Liang Gao, Nan Li, Yushan Xie, Kai Zhu, Hang Yang, Qingze Chen

Abstract: The galaxy-galaxy lensing technique allows us to measure the subhalo mass of satellite galaxies, studying their mass loss and evolution within galaxy clusters and providing direct observational validation for theories of galaxy formation. In this study, we use the weak gravitational lensing observations from DECaLS DR8, in combination with the redMaPPer galaxy cluster catalog from SDSS DR8 to accurately measure the dark matter halo mass of satellite galaxies. We confirm a significant increase in the stellar-to-halo mass ratio of satellite galaxies with their halo-centric radius, indicating clear evidence of mass loss due to tidal stripping. Additionally, we find that this mass loss is strongly dependent on the mass of the satellite galaxies, with satellite galaxies above $10^{11}~{\rm M_{\odot}/h}$ experiencing more pronounced mass loss compared to lower mass satellites, reaching 86\% at projected halo-centric radius $0.5R_{\rm 200c}$. The average mass loss rate, when not considering halo-centric radius, displays a U-shaped variation with stellar mass, with galaxies of approximately $4\times10^{10}~{\rm M_{\odot}/h}$ exhibiting the least mass loss, around 60\%. We compare our results with state-of-the-art hydrodynamical numerical simulations and find that the satellite galaxy stellar-to-halo mass ratio in the outskirts of galaxy clusters is higher compared to the predictions of the Illustris-TNG project about factor 5. Furthermore, the Illustris-TNG project's numerical simulations did not predict the observed dependence of satellite galaxy mass loss rate on satellite galaxy mass.

2.Discovery of a Low-Redshift Hot Dust-Obscured Galaxy

Authors:Guodong Li, Chao-Wei Tsai, Daniel Stern, Jingwen Wu, Roberto J. Assef, Andrew W. Blain, Tanio Díaz-Santos, Peter R. M. Eisenhardt, Roger L. Griffith, Thomas H. Jarrett, Hyunsung D. Jun, Sean E. Lake, M. Lynne Saade

Abstract: We report the discovery of the hyperluminous, highly obscured AGN WISE J190445.04+485308.9 (W1904+4853 hereafter, $L_{bol} = 1.1 \times 10^{13} \ L_{\odot}$) at z=0.415. Its well-sampled spectral energy distribution (SED) is dominated by infrared dust emission, though broad emission lines are detected in the optical spectra. These features suggest that W1904+4853 contains an actively accreting supermassive black hole hidden in its dusty cocoon, resembling the observed properties of Hot Dust-Obscured Galaxies (Hot DOGs), a population previously only identified at z>1.0. Using the broad component of the MgII emission line, we estimate a black hole mass of $log \ (M_{BH}/M_{\odot}) = 8.4 \pm 0.3$. The corresponding Eddington ratio of $1.4 \pm 0.2$ implies that the central black hole accretion is at the theoretical limit of isotropic accretion. The rest-frame UV-optical SED and [O II] emission line also indicate that the host galaxy of W1904+4853 harbors strong star formation activity at the rate of up to $\sim 45 \ M_{\odot} \ yr^{-1}$. With an estimated stellar mass of $3 \times 10^{10} \ M_{\odot}$, the host galaxy appears to be a starburst system with respect to the main sequence of the star-forming galaxies at the same redshift. Although blueshifted and asymmetric [O III] emission provides evidence of an outflow, we estimate it to be an order of magnitude smaller than the star formation rate, indicating that the current obscured AGN activity at the center has not yet produced significant feedback on the host galaxy star formation activity. W1904+4853 supports the interpretation that Hot DOGs are a rare transitional phase of AGN accretion in galaxy evolution, a phase that can persist into the present-day Universe.

3.The impact of early massive mergers on the chemical evolution of Milky Way-like galaxies: insights from NIHAO-UHD simulations

Authors:Tobias Buck Lucy, Aura Obreja Lucy, Bridget Ratcliffe Lucy, Yuxi Lucy, Lu, Ivan Minchev, Andrea V. Macciò

Abstract: Recent observations of the Milky Way (MW) found an unexpected steepening of the star-forming gas metallicity gradient around the time of the Gaia-Sausage-Enceladus (GSE) merger event. Here we investigate the influence of early ($t_{\mathrm{merger}}\lesssim5$ Gyr) massive ($M_{\mathrm{gas}}^{\mathrm{merger}}/M_{\mathrm{gas}}^{\mathrm{main}}(t_{\mathrm{merger}})\gtrsim10\%$) merger events such as the Gaia-Sausage Enceladus merger in the MW on the evolution of the cold gas metallicity gradient. We use the NIHAO-UHD suite of cosmological hydrodynamical simulations of MW-mass galaxies to study the frequency of massive early mergers and their detailed impact on the morphology and chemistry of the gaseous disks. We find a strong steepening of the metallicity gradient at early times for all four galaxies in our sample which is caused by a sudden increase in the cold gas disk size (up to a factor of 2) in combination with the supply of un-enriched gas ($\sim0.75$ dex lower compared to the main galaxy) by the merging dwarf galaxies. The mergers mostly affect the galaxy outskirts and lead to an increase in cold gas surface density of up to 200% outside of $\sim8$ kpc. The addition of un-enriched gas breaks the self-similar enrichment of the inter-stellar-medium and causes a dilution of the cold gas in the outskirts of the galaxies. The accreted stars and the ones formed later out of the accreted gas inhabit distinct tracks offset to lower [$\alpha$/Fe] and [Fe/H] values compared to the main galaxy's stars. We find that such mergers can contribute significantly to the formation of a second, low-$\alpha$ sequence as is observed in the MW.

4.Investigating star formation activity in the Sh 2-61 H II region

Authors:Rakesh Pandey, Saurabh Sharma, Lokesh Dewangan, Aayushi Verma, Tapas Baug, Harmeen Kaur, Arpan Ghosh

Abstract: Using the multiwavelength data sets, we studied the star formation activity in H II region Sh 2-61 (hereafter S61). We identified a clustering in the region and estimated the membership using the Gaia proper motion data. The physical environment of S61 is inspected using infrared to radio wavelength images. We also determined the Lyman continuum flux associated with the H II region and found that the H II region is formed by at least two massive stars (S1 and S2). We also analyzed the 12CO (J =3-2) JCMT data of S61, and a shell structure accompanying three molecular clumps are observed towards S61. We found that the ionized gas in S61 is surrounded by dust and a molecular shell. Many young stellar objects and three molecular clumps are observed at the interface of the ionized gas and the surrounding gas. The pressure at the interface is higher than in a typical cool molecular cloud.

5.Reeling in the Whirlpool: the distance to M 51 clarified by Cepheids and the Type IIP SN 2005cs

Authors:G. Csörnyei, R. I. Anderson, C. Vogl, S. Taubenberger, S. Blondin, B. Leibundgut, W. Hillebrandt

Abstract: Despite being one of the best-known galaxies, the distance to the Whirlpool Galaxy, M 51, is still debated. Current estimates range from 6.02 to 9.09 Mpc, and different methods yield discrepant results. No Cepheid distance has been published for M 51 to date. We aim to estimate a more reliable distance to M 51 through two independent methods: Cepheid variables and their period-luminosity relation, and an augmented version of the expanding photosphere method (EPM) on the Type IIP SN 2005cs. For the Cepheid variables, we analyse a recently published HST catalogue of stars in M 51. By applying light curve and colour-magnitude diagram-based filtering, we select a high-quality sample of M 51 Cepheids to estimate the distance through the period-luminosity relation. For SN 2005cs, an emulator-based spectral fitting technique is applied, which allows for the fast and reliable estimation of physical parameters of the supernova atmosphere. We augment the established framework of EPM with these spectral models to obtain a precise distance to M 51. The two resulting distance estimates are D_Cep = 7.59 +/- 0.30 Mpc and D_2005cs = 7.34 +/- 0.39 Mpc using the Cepheid period-luminosity relation and the spectral modelling of SN 2005cs respectively. This is the first published Cepheid distance for this galaxy. Given that these two estimates are completely independent, one may combine them, which yields D_M51 = 7.50 +/- 0.24 Mpc (3.2% uncertainty). Our distance estimates are in agreement with most of the results obtained previously for M 51, while being more precise than the earlier counterparts. They are however significantly lower than the TRGB estimates, which are often adopted for the distance to this galaxy. The results highlight the importance of direct cross-checks between independent distance estimates for quantifying systematic uncertainties.

6.Pisces VII/Triangulum III -- M33's second dwarf satellite galaxy

Authors:Michelle L. M. Collins, Noushin Karim, David Martinez-Delgado, Matteo Monelli, Erik J. Tollerud, Giuseppe Donatiello, Mahdieh Navabi, Emily Charles, Walter Boschin

Abstract: Pisces VII/Triangulum III (Pisc~VII) was discovered in the DESI Legacy Imaging Survey and was shown to be a Local Group dwarf galaxy with follow-up imaging from the 4-m Telescopio Nazionale Galileo. However, this imaging was unable to reach the horizontal branch of Pisc VII, preventing a precision distance measurement. The distance bound from the red giant branch population placed Pisc VII as either an isolated ultra-faint dwarf galaxy or the second known satellite galaxy of Triangulum (M33). Using deep imaging from Gemini GMOS-N, we have resolved the horizontal branch of Pisc VII, and measure a distance of $D=962^{+32}_{-32}$~kpc, making Pisc VII a likely satellite of M33. We also remeasure its size and luminosity from this deeper data, finding $r_{\rm half}=186^{+58}_{-32}$ pc, $M_V=-5.7\pm0.3$ and $L=1.6^{+0.1}_{-0.2}\times10^4\,{\rm L}_\odot$. Given its position in the M33 halo, we argue that Pisc VII could support the theory that M33 is on its first infall to the Andromeda system. We also discuss the presence of blue stars in the colour-magnitude diagram of Pisc VII that are consistent with ages of 1.5 Gyr. If these are truly members of the galaxy, it would transform our understanding of how reionisation affects the faintest galaxies. However we cannot rule out a more ordinary explanation for these with current data. Future deep imaging and dynamics could allow significant insight into both the stellar populations of Pisc VII and the evolution of M33.

7.Formation of $\text{H}_{2}$ on polycyclic aromatic hydrocarbons under conditions of the ISM: an ab initio molecular dynamics study

Authors:Nicolás F. Barrera, Patricio Fuentealba, Francisco Muñoz, Tatiana Gómez, Carlos Cárdenas

Abstract: Understanding how the $\mathrm{H}_2$ molecule is formed under the chemical conditions of the interstellar media (ISM) is critical to the whole chemistry of it. Formation of $\mathrm{H}_2$ in the ISM requires a third body acting as a reservoir of energy. Polycyclic aromatic hydrocarbons (PAH's) are excellent candidates to play that role. In this work we simulated the collisions of hydrogen atoms with coronene to form $\mathrm{H}_2$ via the Eley-Rideal mechanism. To do so, we used Born-Oppenheimer (ab initio) Molecular Dynamics simulations. Our results show that that adsorption of H atoms and subsequent release of $\mathrm{H}_2$ readily happen on coronene for H atoms with kinetic energy as large as 1 eV. Special attention is paid to dissipation and partition of the energy released in the reactions. The capacity of coronene to dissipate collision and reaction energies depends varies with the reaction site. Inner sites dissipate energy easier and faster than edge sites, thus evidencing an interplay between the potential energy surface around the reaction center and its ability to cool the projectile. As for the the recombination of H atoms and the subsequent formation of $\mathrm{H}_{2}$, it is observed that $\sim 15\%$ of the energy is dissipated by the coronene molecule as vibrational energy and the remaining energy is carried by $\mathrm{H}_{2}$. The $\mathrm{H}_{2}$ molecules desorb from coronene with an excited vibrational state ($\upsilon \geq 3$), a large amount of translational kinetic energy ($\geq$ 0.4 eV) and with a small activation of the rotational degree of freedom.

8.COOL-LAMPS. V. Discovery of COOL J0335$-$1927, a Gravitationally Lensed Quasar at $z$=3.27 with an Image Separation of 23.3"

Authors:Kate Napier, Mike Gladders, Keren Sharon, Håkon Dahle, Aidan P. Cloonan, Guillaume Mahler, Isaiah Escapa, Josh Garza, Andrew Kisare, Natalie Malagon, Simon Mork, Kunwanhui Niu, Riley Rosener, Jamar Sullivan Jr., Marie Tagliavia, Marcos Tamargo, Raul Teixeira, Kabelo Tsiane, Grace Wagner, Yunchong Zhang, Megan Zhao

Abstract: We report the discovery of COOL J0335$-$1927, a quasar at $z$ = 3.27 lensed into three images with a maximum separation of 23.3" by a galaxy cluster at $z$ = 0.4178. We construct a parametric strong gravitational lens model using ground-based imaging, constrained by the redshift and positions of the quasar images as well as the positions of three other multiply-imaged background galaxies. Using our best-fit lens model, we calculate the predicted time delays between the three quasar images to be $\Delta$t$_{AB}=$ $241^{+41}_{-12}$ and $\Delta$t$_{AC}=$ $-64^{+3}_{-33}$ days. We also present g-band photometry from archival DECaLS imaging, and new multi-epoch observations obtained between September 18, 2022 UT and February 22, 2023 UT, which demonstrate significant variability in the quasar and which will eventually enable a measurement of the time delay between the three quasar images.

1.Halo formation and evolution in SFDM and CDM: new insights from the fluid approach

Authors:Horst Foidl, Tanja Rindler-Daller, Werner Zeilinger

Abstract: (abridged) We present simulations of halo formation and evolution in scalar field dark matter (SFDM) cosmologies in the Thomas-Fermi regime, aka ``SFDM-TF", where a strong repulsive 2-particle self-interaction (SI) is included, being a valuable alternative to CDM, with the potential to resolve its ``cusp-core" problem. In general, SFDM behaves like a quantum fluid. Previous literature has presented two fluid approximations for SFDM-TF, as well as simulations of halo formation. These results confirmed earlier expectations and are generally in mutual agreement, but discrepancies were also reported. Therefore, we perform dedicated 3D cosmological simulations for the SFDM-TF model, applying both fluid approximations, as well as for CDM. Our results are very well in accordance with previous works and extend upon them, in that we can explain the reported discrepancies as a result of different simulation setups. We find some interesting details: The evolution of both SFDM-TF and CDM halos follows a 2-stage process. In the early stage, the density profile in the center becomes close to a $(n=1.5)$-polytropic core, dominated by an "effective" velocity-dispersion pressure $P_{\sigma}$ which is common to both dark matter models. Consecutively, for CDM halos, the core transitions into a central cusp. In SFDM-TF halos, the additional pressure $P_\text{SI}$ due to SI determines the second stage of the evolution, where the central region follows closely a $(n=1)$-polytropic core, embedded in a nearly isothermal envelope, i.e. the outskirts are similar to CDM. We also encounter a new effect, namely a late-time expansion of both polytropic core plus envelope, because the size of the almost isothermal halo envelope is affected by the expansion of the background universe. So, an initial primordial core of $\sim 100$ pc can evolve into a larger core of $\gtrsim 1$ kpc, even without feedback from baryons.

2.High Sensitivity Observations of the Water Megamasers of NGC 1068: Precise Astrometry and Detailed Kinematics

Authors:Jack F. Gallimore, C. M. Violette Impellizzeri

Abstract: We present High Sensitivity Array observation of the water megamasers of NGC 1068. We obtain absolute astrometry with 0.3 mas precision that confirms the association of the disk masers with the nuclear radio continuum source S1. The new observations reveal two new blueshifted groups of disk masers. We also detect the 22 GHz continuum on short interferometric baselines. The position-velocity diagram of the disk masers shows a curve consistent with a nonaxisymmetric distribution of maser spots. The curve is probably the result of spiral arms with a constant pitch angle of roughly 5 degrees. The disk kinematics are consistent with Keplerian rotation and low turbulent speeds. The inferred central mass is 17 million solar masses. On the basis of disk stability arguments, the mass of the molecular disk is roughly 110 thousand solar masses. The disk masers further resolve into filamentary structures suggesting an ordered magnetic field threading the maser disk. The magnetic field strengths must be greater than 1.6 mG to withstand turbulent motions in the partially ionized molecular gas. We note apparent asymmetries in the molecular disk that might be explained by anisotropic heating by a misaligned inner accretion disk. The new observations also detect the fainter jet masers north of the disk masers. The distribution and kinematics of the jet masers are consistent with an expanding ring of molecular gas.

3.Density biases and temperature relations for DESIRED HII regions

Authors:J. E. Méndez-Delgado, C. Esteban, J. García-Rojas, K. Z. Arellano-Córdova, K. Kreckel, V. Gómez-Llanos, O. V. Egorov, M. Peimbert, M. Orte-García

Abstract: We present a first study based on the analysis of the DEep Spectra of Ionized REgions Database (DESIRED). This is a compilation of 190 high signal-to-noise ratio optical spectra of HII regions and other photoionized nebulae, mostly observed with 8-10m telescopes and containing $\sim$29380 emission lines. We find that the electron density --$n_{\rm e}$-- of the objects is underestimated when [SII] $\lambda6731/\lambda6716$ and/or [OII] $\lambda3726/\lambda3729$ are the only density indicators available. This is produced by the non-linear density dependence of the indicators in the presence of density inhomogeneities. The average underestimate is $\sim 300$ cm$^{-3}$ in extragalactic HII regions, introducing systematic overestimates of $T_{\rm e}$([OII]) and $T_{\rm e}$([SII]) compared to $T_{\rm e}$([NII]). The high-sensitivity of [OII] $\lambda\lambda7319+20+30+31/\lambda\lambda3726+29$ and [SII] $\lambda\lambda4069+76/\lambda\lambda6716+31$ to density makes them more suitable for the diagnosis of the presence of high-density clumps. If $T_{\rm e}$([NII]) is adopted, the density underestimate has a small impact in the ionic abundances derived from optical spectra, being limited to up to $\sim$0.1 dex when auroral [SII] and/or [OII] lines are used. However, these density effects are critical for the analysis of infrared fine structure lines, such as those observed by the JWST in local star forming regions, implying strong underestimates of the ionic abundances. We present temperature relations between $T_{\rm e}$([OIII]), $T_{\rm e}$([ArIII]), $T_{\rm e}$([SIII]) and $T_{\rm e}$([NII]) for the extragalactic HII regions. We confirm a non-linear dependence between $T_{\rm e}$([OIII])-$T_{\rm e}$([NII]) due to a more rapid increase of $T_{\rm e}$([OIII]) at lower metallicities.

4.The MeerKAT Fornax Survey -- II. The rapid removal of HI from dwarf galaxies in the Fornax cluster

Authors:D. Kleiner, P. Serra, F. M. Maccagni, M. A. Raj, W. J. G. de Blok, G. I. G. Józsa, P. Kamphuis, R. Kraan-Korteweg, F. Loi, A. Loni, S. I. Loubser, D. Cs. Molnár, T. A. Oosterloo, R. Peletier, D. J. Pisano

Abstract: We present MeerKAT Fornax Survey atomic hydrogen (HI) observations of the dwarf galaxies located in the central ~2.5 x 4 deg$^2$ of the Fornax galaxy cluster. The HI images presented in this work have a $3\sigma$ column density sensitivity between 2.7 and 50 x 10$^{18}$ cm$^{-2}$ over 25 km s$^{-1}$ for spatial resolution between 4 and 1 kpc. We are able to detect an impressive MHI = 5 x 10$^{5}$ Msun 3$\sigma$ point source with a line width of 50 km s$^{-1}$ at a distance of 20 Mpc. We detect HI in 17 out of the 304 dwarfs in our field -- 14 out of the 36 late type dwarfs (LTDs), and 3 of the 268 early type dwarfs (ETDs). The HI-detected LTDs have likely just joined the cluster and are on their first infall as they are located at large clustocentric radii, with comparable MHI and mean stellar surface brightness at fixed luminosity as blue, star-forming LTDs in the field. The HI-detected ETDs have likely been in the cluster longer than the LTDs and acquired their HI through a recent merger or accretion from nearby HI. Eight of the HI-detected LTDs host irregular or asymmetric HI emission and disturbed or lopsided stellar emission. There are two clear cases of ram-pressure shaping the HI, with the LTDs displaying compressed HI on the side closest to the cluster centre and a one-sided, starless tail pointing away from the cluster centre. The HI-detected dwarfs avoid the most massive potentials, consistent with massive galaxies playing an active role in the removal of HI. We create a simple toy model to quantify the timescale of HI stripping in the cluster. We find that a MHI = 10$^{8}$ Msun dwarf will be stripped in ~ 240 Myr. The model is consistent with our observations, where low mass LTDs are directly stripped of their HI from a single encounter and more massive LTDs can harbour a disturbed HI morphology due to longer times or multiple encounters being required to fully strip their HI.

5.A panoptic view of the Taurus molecular cloud I. The cloud dynamics revealed by gas emission and 3D dust

Authors:J. D. Soler, C. Zucker, J. E. G. Peek, M. Heyer, P. F. Goldsmith, S. C. O. Glover, S. Molinari, R. S. Klessen, P. Hennebelle, L. Testi, T. Colman, M. Benedettini, D. Elia, C. Mininni, S. Pezzuto, E. Schisano, A. Traficante

Abstract: We present a study of the three-dimensional (3D) distribution of interstellar dust derived from stellar extinction observations toward the Taurus molecular cloud (MC) and its relation with the neutral atomic hydrogen (HI) emission at 21 cm wavelength and the carbon monoxide $^{12}$CO and $^{13}$CO emission in the $J=1\rightarrow0$ transition. We used the histogram of oriented gradients (HOG) method to match the morphology in a 3D reconstruction of the dust density (3D dust) and the distribution of the gas tracers' emission. The result of the HOG analysis is a map of the relationship between the distances and radial velocities. The HOG comparison between the 3D dust and the HI emission indicates a morphological match at the distance of Taurus but an anti-correlation between the dust density and the HI emission, which uncovers a significant amount of cold HI within the Taurus MC. The HOG between the 3D dust and $^{12}$CO reveals a pattern in radial velocities and distances that is consistent with converging motions of the gas in the Taurus MC, with the near side of the cloud moving at higher velocities and the far side moving at lower velocities. This convergence of flows is likely triggered by the large-scale gas compression caused by the interaction of the Local Bubble and the Per-Tau shell, with Taurus lying at the intersection of the two bubble surfaces.

1.Temperature inhomogeneities cause the abundance discrepancy in H II regions

Authors:J. Eduardo Méndez-Delgado, César Esteban, Jorge García-Rojas, Kathryn Kreckel, Manuel Peimbert

Abstract: HII regions, ionized nebulae where massive star formation has taken place, exhibit a wealth of emission lines that are the fundamental basis for estimating the chemical composition of the Universe. For more than 80 years, a discrepancy of at least a factor of two between heavy-element abundances derived with collisional excited lines (CELs) and the weaker recombination lines (RLs) has thrown our absolute abundance determinations into doubt. Heavy elements regulate the cooling of the interstellar gas, being essential to the understanding of several phenomena such as nucleosynthesis, star formation and chemical evolution. In this work, we use the best available deep optical spectra of ionized nebulae to analyze the cause of this abundance discrepancy problem. We find for the first time general observational evidence in favor of the temperature inhomogeneities within the gas, quantified by t2. The temperature inhomogeneities inside H II regions are affecting only the gas of high ionization degree and producing the abundance discrepancy problem. This work implies that the metallicity determinations based on CELs must be revised, as they can be severely underestimated, especially in the regions of lower metallicity, such as the JWST high-z galaxies. We present methods to estimate these corrections, which will be critical for robust interpretations of the chemical composition of the Universe over cosmic time.

2.Rotation-tunneling spectrum and astrochemical modeling of dimethylamine, CH$_3$NHCH$_3$, and searches for it in space

Authors:H. S. P. Müller, R. T. Garrod, A. Belloche, V. M. Rivilla, K. M. Menten, I. Jiménez-Serra, J. Martín-Pintado, F. Lewen, S. Schlemmer

Abstract: Methylamine has been the only simple alkylamine detected in the interstellar medium for a long time. With the recent secure and tentative detections of vinylamine and ethylamine, respectively, dimethylamine has become a promising target for searches in space. Its rotational spectrum, however, has been known only up to 45 GHz until now. Here we investigate the rotation-tunneling spectrum of dimethylamine in selected regions between 76 and 1091 GHz using three different spectrometers in order to facilitate its detection in space. The quantum number range is extended to $J = 61$ and $K_a = 21$, yielding an extensive set of accurate spectroscopic parameters. To search for dimethylamine, we refer to the spectral line survey ReMoCA carried out with the Atacama Large Millimeter/submillimeter Array toward the high-mass star-forming region Sagittarius B2(N) and a spectral line survey of the molecular cloud G+0.693$-$0.027 employing the IRAM 30 m and Yebes 40 m radio telescopes. We report nondetections of dimethylamine toward the hot molecular cores Sgr B2(N1S) and Sgr B2(N2b) as well as G+0.693$-$0.027 which imply that dimethylamine is at least 14, 4.5 and 39 times less abundant than methylamine toward these sources, respectively. The observational results are compared to computational results from a gas-grain astrochemical model. The modeled methylamine to dimethylamine ratios are compatible with the observational ratios. However, the model produces too much ethylamine compared with methylamine which could mean that the already fairly low levels of dimethylamine in the models may also be too high.

3.Powerful Radio-Loud Quasars are Triggered by Galaxy Mergers in the Cosmic Bright Ages

Authors:Peter Breiding, Marco Chiaberge, Erini Lambrides, Eileen T. Meyer, S. P. Willner, Bryan Hilbert, Martin Haas, George Miley, Eric S. Perlman, Peter Barthel, Christopher P. O'Dea, Alessandro Capetti, Belinda Wilkes, Stefi A. Baum, Duccio F. Macchetto, Grant Tremblay, Colin Norman

Abstract: While supermassive black holes are ubiquitous features of galactic nuclei, only a small minority are observed during episodes of luminous accretion. The physical mechanism(s) driving the onset of fueling and ignition in these active galactic nuclei (AGN) are still largely unknown for many galaxies and AGN-selection criteria. Attention has focused on AGN triggering by means of major galaxy mergers gravitationally funneling gas towards the galactic center, with evidence both for and against this scenario. However, several recent studies have found that radio-loud AGN overwhelmingly reside in ongoing or recent major galaxy mergers. In this study, we test the hypothesis that major galaxy mergers are important triggers for radio-loud AGN activity in powerful quasars during cosmic noon (1 < z < 2). To this end, we compare Hubble Space Telescope WFC3/IR observations of the z > 1 3CR radio-loud broad-lined quasars to three matched radio-quiet quasar control samples. We find strong evidence for major-merger activity in nearly all radio-loud AGN, in contrast to the much lower merger fraction in the radio-quiet AGN. These results suggest major galaxy mergers are key ingredients to launching powerful radio jets. Given many of our radio-loud quasars are blue, our results present a possible challenge to the "blow-out" paradigm of galaxy evolution models in which blue quasars are the quiescent end result following a period of red quasar feedback initiated by a galaxy merger. Finally, we find a tight correlation between black hole mass and host galaxy luminosity for these different high-redshift AGN samples inconsistent with those observed for local elliptical galaxies.

4.MUSE AO spectroscopy confirms five dual AGNs and two strongly lensed QSOs at sub-arcsec separation

Authors:M. Scialpi, F. Mannucci, C. Marconcini, G. Venturi, E. Pancino, A. Marconi, G. Cresci, F. Belfiore, A. Amiri, E. Bertola, S. Carniani, C. Cicone, A. Ciurlo, M. Ginolfi, E. Lusso, A. Marasco, E. Nardini, K. Rubinur, P. Severgnini, G. Tozzi, L. Ulivi, M. Volonteri

Abstract: The novel Gaia Multi Peak (GMP) technique has proven to be able to successfully select dual and lensed AGN candidates at sub-arcsec separations. Both populations are important because dual AGNs represent one of the central, still largely untested, predictions of lamdaCDM cosmology, and compact lensed quasars allow to probe the central regions of the lensing galaxies. In this work, we present high spatial resolution spectroscopy of twelve GMP-selected systems. We use the the adaptive-optics assisted integral-field spectrograph MUSE at VLT to resolve each system and study the nature of each component. All the targets reveal the presence of two components confirming the GMP selection. We classify five targets as dual AGNs, two as lensed systems, and five as a chance alignment of a star and and AGN. Having separations between 0.30" and 0.86", these dual and lensed systems are, to date, among the most compact ever discovered at z >0.3. This is the largest sample of distant dual AGNs with sub-arcsec separations ever presented in a single paper.

1.HI Self-absorption toward the Cygnus X North: From Atomic Filament to Molecular Filament

Authors:Chong Li, Keping Qiu, Di Li, Hongchi Wang, Yue Cao, Junhao Liu, Yuehui Ma, Chenglin Yang

Abstract: Using the HI self-absorption data from the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we perform a study of the cold atomic gas in the Cygnus-X North region. The most remarkable HI cloud is characterized by a filamentary structure, associated in space and in velocity with the principle molecular filament in the Cygnus-X North region. We investigate the transition from the atomic filament to the molecular filament. We find that the HII regions Cygnus OB2 and G081.920+00.138 play a critical role in compressing and shaping the atomic Cygnus-X North filament, where the molecular filament subsequently forms. The cold HI in the DR21 filament has a much larger column density (N(HI) $\sim$ 1 $\times$ 10$^{20}$ cm$^{-2}$) than the theoretical value of the residual atomic gas ($\sim$ 1 $\times$ 10$^{19}$ cm$^{-2}$), suggesting that the HI-to-H$_2$ transition is still in progress. The timescale of the HI-to-H$_2$ transition is estimated to be 3 $\times$ 10$^{5}$ yr, which approximates the ages of massive protostars in the Cygnus-X North region. This implies that the formation of molecular clouds and massive stars may occur almost simultaneously in the DR21 filament, in accord with a picture of rapid and dynamic cloud evolution.

2.Dissecting the RELICS cluster SPT-CLJ0615-5746 through the intracluster light: confirmation of the multiple merging state of the cluster formation

Authors:Y. Jiménez-Teja, R. A. Dupke, P. A. A. Lopes, J. M. Vílchez

Abstract: The intracluster light (ICL) fraction, measured at certain specific wavelengths, has been shown to provide a good marker for determining the dynamical stage of galaxy clusters, i.e., merging versus relaxed, for small to intermediate redshifts. Here, we apply it for the first time to a high-redshift system, SPT-CLJ0615-5746 at z=0.97, using its RELICS (Reionization Lensing Cluster Survey) observations in the optical and infrared. We find the ICL fraction signature of merging, with values ranging from 16 to 37%. A careful re-analysis of the X-ray data available for this cluster points to the presence of at least one current merger, and plausibly a second merger. These two results are in contradiction with previous works based on X-ray data, which claimed the relaxed state of SPT-CLJ0615-5746, and confirmed the evidences presented by kinematic analyses. We also found an abnormally high ICL fraction in the rest-frame near ultraviolet wavelengths, which may be attributed to the combination of several phenomena such as an ICL injection during recent mergers of stars with average early-type spectra, the reversed star formation-density relation found at this high redshift in comparison with lower-redshift clusters, and projection effects.

3.What boost galaxy mergers in two massive galaxy protoclusters at z = 2.24

Authors:Shuang Liu, Xianzhong Zheng, Dongdong Shi, Zheng Cai, Xiaohui Fan, Xin Wang, Qirong Yuan, Haiguang Xu, Zhizheng Pan, Wenhao Liu, Jianbo Qin, Yuheng Zhang, Run Wen

Abstract: Characterizing the structural properties of galaxies in high-redshift protoclusters is key to our understanding of the environmental effects on galaxy evolution in the early stages of galaxy and structure formation. In this study, we assess the structural properties of 85 and 87 Halpha emission-line candidates (HAEs) in the densest regions of two massive protoclusters, BOSS1244 and BOSS1542, respectively, using HST H-band imaging data. Our results show a true pair fraction of 22+-5 (33+-6) percent in BOSS1244 (BOSS1542), which yields a merger rate of 0.41+-0.09 (0.52+-0.04) per Gyr for massive HAEs with log (M_*/M_sun) > 10.3. This rate is 1.8 (2.8) times higher than that of the general fields at the same epoch. Our sample of HAEs exhibits half-light radii and Sersic indices that cover a broader range than field star-forming galaxies. Additionally, about 15 percent of the HAEs are as compact as the most massive (log(M_*/M_sun) > 11) spheroid-dominated population. These results suggest that the high galaxy density and cold dynamical state (i.e., velocity dispersion of <400 km/s) are key factors that drive galaxy mergers and promote structural evolution in the two protoclusters. Our findings also indicate that both the local environment (on group scales) and the global environment play essential roles in shaping galaxy morphologies in protoclusters. This is evident in the systematic differences observed in the structural properties of galaxies between BOSS1244 and BOSS1542.

4.A Multi-Wavelength Investigation of Dust and Stellar Mass Distributions in Galaxies: Insights from High-Resolution JWST Imaging

Authors:Zhaoran Liu, Takahiro Morishita, Tadayuki Kodama

Abstract: We study the morphological properties of mid-infrared selected galaxies at $1.0<z<1.7$ in the SMACS J0723.3-7327 cluster field, to investigate the mechanisms of galaxy mass assembly and structural formation at cosmic noon. We develop a new algorithm to decompose the dust and stellar components of individual galaxies by utilizing high-resolution images in the MIRI F770W and NIRCam F200W bands. Our analyses reveal that most galaxies in the stellar mass range ${\rm 10^{9.5}<M_*/M_\odot<10^{10.5}}$ have dust cores relatively compact compared to their stellar cores, whereas the most massive ($\rm{M_* \sim 10^{10.9}\,M_\odot}$) galaxy in our sample displays a comparably compact stellar core as to dust. The observed compactness of the dust component is potentially attributed to the presence of a (rapidly growing) massive bulge, in some cases associated with elevated star formation. Expanding the sample size through a joint analysis of multiple Cycle~1 deep-imaging programs can help to confirm the inferred picture. Our pilot study highlights that MIRI offers an efficient approach to studying the structural formation of galaxies from cosmic noon to the modern universe.

5.Equilibrium dynamical models for the Large Magellanic Cloud

Authors:Nikolay Kacharov, Maria-Rosa L. Cioni

Abstract: The Large Magellanic Cloud (LMC) has a complex dynamics driven by both internal and external processes. The external forces are due to tidal interactions with the Small Magellanic Cloud and the Milky Way, while internally its dynamics mainly depends on the stellar, gas, and dark matter mass distributions. Despite the overall complexity of the system, very often simple physical models can give us important insights about the main driving factors. Here we focus on the internal forces and attempt to model the proper motions of $\sim10^6$ stars in the LMC as measured by Gaia Data Release 3 with an axisymmetric dynamical model, based on the Jeans equations. We test both cored and cusped spherical Navarro-Frenk-White dark matter halos to fit the LMC gravitational potential. We find that this simple model is very successful at selecting a clean sample of genuine LMC member stars and predicts the geometry and orientation of the LMC with respect to the observer within the constraint of axisymmetry. Our Jeans dynamical models describe well the rotation profile and the velocity dispersion of the LMC stellar disc, however they fail to describe the motions of the LMC bar, which is a non-axisymmetric feature dominating the central region. We plan a triaxial Schwarzschild approach as a next step for the dynamical modelling of the LMC.

1.Magnetic Fields and Fragmentation of Filaments in the Hub of California-X

Authors:Eun Jung Chung, Chang Won Lee, Woojin Kwon, Mario Tafalla, Shinyoung Kim, Archana Soam, Jungyeon Cho

Abstract: We present 850 $\mu$m polarization and $\rm C^{18}O (3-2)$ molecular line observations toward the X-shaped nebula in the California molecular cloud using the JCMT SCUBA-2/POL-2 and HARP instruments. The 850 $\mu$m emission shows that the observed region includes two elongated filamentary structures (Fil1 and Fil2) having chains of regularly spaced cores. We measured the mass per unit length of the filament and found that Fil1 and Fil2 are thermally super- and subcritical, respectively, but both are subcritical if nonthermal turbulence is considered. The mean projected spacings ($\Delta\bar S$) of cores in Fil1 and Fil2 are 0.13 and 0.16 pc, respectively. $\Delta\bar S$ are smaller than $4\times$filament width expected in the classical cylinder fragmentation model. The large-scale magnetic field orientations shown by Planck are perpendicular to the long axes of Fil1 and Fil2, while those in the filaments obtained from the high-resolution polarization data of JCMT are disturbed, but those in Fil1 tend to have longitudinal orientations. Using the modified Davis-Chandrasekhar-Fermi (DCF) method, we estimated the magnetic field strengths ($B_{\rm pos}$) of filaments which are 110$\pm$80 and 90$\pm$60 $\mu$G. We calculated the gravitational, kinematic, and magnetic energies of the filaments, and found that the fraction of magnetic energy is larger than 60 % in both filaments. We propose that a dominant magnetic energy may lead the filament to be fragmented into aligned cores as suggested by Tang et al., and a shorter core spacing can be due to a projection effect via the inclined geometry of filaments or due to a non-negligible, longitudinal magnetic fields in case of Fil1.

2.Warm Molecular Gas in the Central Parsecs of the Buried Nucleus of NGC 4418 Traced with the Fundamental CO Ro-vibrational Absorptions

Authors:Youichi Ohyama, Shusuke Onishi, Takao Nakagawa, Kosei Matsumoto, Naoki Isobe, Mai Shirahata, Shunsuke Baba, Kazushi Sakamoto

Abstract: We investigated the inner buried nucleus of a nearby luminous infrared galaxy NGC 4418 using high-resolution spectroscopy of fundamental carbon monoxide (CO) ro-vibrational absorptions around $4.67 \mu$m for the first time. This method allowed us to examine the physical and kinematical properties in the hot inner region of this nucleus. We detected a series of both very deep (partly saturated) $^{12}$CO and moderately deep (optically thin) $^{13}$CO absorption lines and inferred a large column density ($N_\mathrm{H2}=(5\pm3)\times10^{23}$ cm$^{-2}$ in front of the $5 \mu$m photosphere) of warm ($T_\mathrm{ex}\simeq170$ K) molecular gas by assuming an isothermal plane-parallel slab illuminated by a compact background MIR-emitting source. We modeled that the warm CO absorber almost covers the central heating source and that it is an inner layer around the $5 \mu$m photosphere (at $r=$several pc) of a compact shroud of gas and dust ($d\sim100$ pc). The width of the absorption lines ($110$ km s$^{-1}$) and their small deviation from the systemic velocity ($<10$ km s$^{-1}$) are consistent with a warm and turbulent layer with little bulk motion in the radial direction.

3.Role of magnetic pressure forces in Fluctuation dynamo saturation

Authors:Sharanya Sur, Kandaswamy Subramanian

Abstract: Using magnetohydrodynamic simulations of Fluctuation dynamos in turbulent flows with rms Mach numbers $\mathcal{M} \approx 0.2, 1.1$ and $3$, we show that magnetic pressure forces play a crucial role in dynamo saturation in supersonic flows. Firstly, as expected when pressure forces oppose compression, an increase in anti-correlation between density and magnetic field strengths obtains even in subsonic flows with the anti-correlation arising from the intense but rarer magnetic structures. In supersonic flows, due to stronger compressive motions density and magnetic field strength continue to maintain a positive correlation. However, the degree of positive correlation decreases as the dynamo saturates. Secondly, we find that the unit vectors of $\nabla\rho$ and $\nabla B^{2}$ are preferentially anti-parallel to each other in subsonic flows. This is indicative of magnetic pressure opposing compression. This anti-parallel alignment persists in transonic and supersonic flows at dynamo saturation. However, compressive motions also lead to the emergence of a parallel alignment in these flows. Finally, we consider the work done against the components of the Lorentz force and the different sources of magnetic energy growth and dissipation. We show that while in subsonic flows, suppression of field line stretching is dominant in saturating the dynamo, the picture is different in supersonic flows. Both field line stretching and compression amplifies the field initially. But the growing magnetic pressure opposes further compression of magnetic flux which then dominates the saturation of the dynamo.

4.Investigating kinematics and dynamics of three open clusters towards Galactic anti-center

Authors:Geeta Rangwal, R. K. S. Yadav, D. Bisht, Alok Durgapal, Devesh P. Sariya

Abstract: We present the intra-cluster kinematics and dynamics of three open clusters: NGC 1193, NGC 2355, and King 12 by incorporating kinematical and photometric data from Gaia DR3, as well as a ground-based telescope. After selecting cluster members based on proper motion data, clusters' fundamental and structural parameters are investigated. We found the clusters at distances of 4.45, 1.97, and 3.34 kpc from the Sun in the direction of the Galactic anticenter. The luminosity function of the cluster NGC 1193 is flat, whereas it advances towards the fainter ends of the other two clusters. We observed a dip in the luminosity function of King 12. The mass function slopes for all three clusters differ from the solar neighbourhood reported by Salpeter, with NGC 1193 and NGC 2355 being flatter and King 12 having a higher value than the Salpeter value. The intra-cluster kinematics depict that stars in King 12 are moving outwards due to tidal forces from the Galactic disc, which we confirmed by plotting the cluster's orbit in the Galaxy. Stars in NGC 2355 are moving with smaller relative velocities and have zero mean relative motion, which signifies that the cluster is neither contracting nor evaporating. The Galactic orbits of NGC 1193 suggest that it is orbiting farther from the Galactic disc, and so is less impacted by the Galactic tidal forces.

5.Simulating the diversity of shapes of the Lyman-$α$ line

Authors:Jeremy Blaizot, Thibault Garel, Anne Verhamme, Harley Katz, Taysun Kimm, Léo Michel-Dansac, Peter D. Mitchell, Joakim Rosdahl, Maxime Trebitsch

Abstract: The Ly$\alpha$ line is a powerful probe of distant galaxies, which contains information about inflowing/outflowing gas through which Ly$\alpha$ photons scatter. To develop our understanding of this probe, we post-process a zoom-in radiation-hydrodynamics simulation of a low-mass ($M_* \sim 10^9 M_\odot$) galaxy to construct 22500 mock spectra in 300 directions from $z = 3$ to 4. Remarkably, we show that one galaxy can reproduce the variety of a large sample of spectroscopically observed Ly$\alpha$ line profiles. While most mock spectra exhibit double-peak profiles with a dominant red peak, their shapes cover a large parameter space in terms of peak velocities, peak separation and flux ratio. This diversity originates from radiative transfer effects at ISM and CGM scales, and depends on galaxy inclination and evolutionary phase. Red-dominated lines preferentially arise in face-on directions during post-starburst outflows and are bright. Conversely, accretion phases usually yield symmetric double peaks in the edge-on direction and are fainter. While resonant scattering effects at $< 0.2\times R_{\rm vir}$ are responsible for the broadening and velocity shift of the red peak, the extended CGM acts as a screen and impacts the observed peak separation. The ability of simulations to reproduce observed Ly$\alpha$ profiles and link their properties with galaxy physical parameters offers new perspectives to use Ly$\alpha$ to constrain the mechanisms that regulate galaxy formation and evolution. Notably, our study implies that deeper Ly$\alpha$ surveys may unveil a new population of blue-dominated lines tracing inflowing gas.

6.A deep study of open cluster NGC 5288 using photometric and astrometric data from Gaia DR3 and 2MASS

Authors:Ritika Sethi, D. Bisht, Geeta Rangwal, A. Raj

Abstract: This paper investigates a poorly studied open cluster, NGC 5288, using 2MASS JHKS and the recently released Gaia DR3 astrometric and photometric data. The mean proper motions in Right Ascension and Declination are estimated as (-3.840 +/- 0.230) and (-1.934 +/- 0.162) mas/yr, respectively. We also derive the age and distance of the cluster as 510 +/- 190 Myr and 2.64 +/- 0.11 kpc, using colour-magnitude diagrams (CMDs). We have also obtained distance as 2.77 +/- 0.42 kpc using the parallax method. Interstellar reddening E(B-V) in the direction of the cluster is determined as 0.45 mag using the ((J - H), (J - K)) colour-colour diagram. We have found the mass function slope for main-sequence stars as 1.39 +/- 0.29 within the mass range 1.0 - 2.7 solar mass, which agrees with Salpeter's value within uncertainty. Galactic orbits are derived using the Galactic potential model, indicating that NGC 5288 follows a circular path around the Galactic center.

7.The Tiered Radio Extragalactic Continuum (T-RECS) simulation II: HI emission and continuum-HI cross-correlation

Authors:Anna Bonaldi, Philippa Hartley, Tommaso Ronconi, Gianfranco De Zotti, Matteo Bonato

Abstract: In this paper we extend the Tiered Radio Extragalactic Continuum Simulation (T-RECS) to include HI emission. The HI T-RECS model is based on the most recent HI mass function estimates, combined with prescriptions to convert HI mass to total integrated HI flux. It further models source size, morphology and kinematics, including rotational velocity and HI line width. The continuum T-RECS model is updated to improve the agreement with deeper number counts available at 150\,MHz. The model for star-forming galaxies (SFGs) is also modified according to the most recent indications of a star formation rate (SFR)--radio luminosity relation, which depends primarily on stellar mass rather than redshift. We further introduce prescriptions to associate an HI mass to the T-RECS radio continuum SFG and Active Galactic Nuclei (AGN) populations. This gives us a way to meaningfully associate counterparts between HI and continuum catalogues, thus building HI $\times$ continuum simulated observations. Clustering properties of the sources in both HI and continuum are reproduced by associating the galaxies to dark matter haloes of a cosmological simulation. We deliver a set of mock catalogues, as well as the code to produce them, which can be used for simulating observations and predicting results from radio surveys with existing and forthcoming radio facilities, such as the Square Kilometre Array (SKA)

8.Panchromatic simulated galaxy observations from the NIHAO project

Authors:Nicholas Faucher, Michael R. Blanton, Andrea V. Macciò

Abstract: We present simulated galaxy spectral energy distributions (SEDs) from the far ultraviolet through the far infrared, created using hydrodynamic simulations and radiative transfer calculations, suitable for the validation of SED modeling techniques. SED modeling is an essential tool for inferring star formation histories from nearby galaxy observations, but is fraught with difficulty due to our incomplete understanding of stellar populations, chemical enrichment processes, and the non-linear, geometry dependent effects of dust on our observations. Our simulated SEDs will allow us to assess the accuracy of these inferences against galaxies with known ground truth. To create the SEDs, we use simulated galaxies from the NIHAO suite and the radiative transfer code SKIRT. We explore different sub-grid post-processing recipes, using color distributions and their dependence on axis ratio of galaxies in the nearby universe to tune and validate them. We find that sub-grid post-processing recipes that mitigate limitations in the temporal and spatial resolution of the simulations are required for producing FUV to FIR photometry that statistically reproduce the colors of galaxies in the nearby universe. With this paper we release resolved photometry and spatially integrated spectra for our sample galaxies, each from a range of different viewing angles. Our simulations predict that there is a large variation in attenuation laws among galaxies, and that from any particular viewing angle that energy balance between dust attenuation and reemission can be violated by up to a factor of 3. These features are likely to affect SED modeling accuracy.

9.Spectral Stacking of Radio-Interferometric Data

Authors:Lukas Neumann, Jakob S. den Brok, Frank Bigiel, Adam Leroy, Antonio Usero, Ashley T. Barnes, Ivana Bešlić, Cosima Eibensteiner, Malena Held, María J. Jiménez-Donaire, Jérôme Pety, Erik W. Rosolowsky, Eva Schinnerer, Thomas G. Williams

Abstract: Mapping molecular line emission beyond the bright low-J CO transitions is still challenging in extragalactic studies, even with the latest generation of (sub-)mm interferometers, such as ALMA and NOEMA. We summarise and test a spectral stacking method that has been used in the literature to recover low-intensity molecular line emission, such as HCN(1-0), HCO+(1-0), and even fainter lines in external galaxies. The goal is to study the capabilities and limitations of the stacking technique when applied to imaged interferometric observations. The core idea of spectral stacking is to align spectra of the low S/N spectral lines to a known velocity field calculated from a higher S/N line expected to share the kinematics of the fainter line, e.g., CO(1-0) or 21-cm emission. Then these aligned spectra can be coherently averaged to produce potentially high S/N spectral stacks. Here, we use imaged simulated interferometric and total power observations at different signal-to-noise levels, based on real CO observations. For the combined interferometric and total power data, we find that the spectral stacking technique is capable of recovering the integrated intensities even at low S/N levels across most of the region where the high S/N prior is detected. However, when stacking interferometer-only data for low S/N emission, the stacks can miss up to 50% of the emission from the fainter line. A key result of this analysis is that the spectral stacking method is able to recover the true mean line intensities in low S/N cubes and to accurately measure the statistical significance of the recovered lines. To facilitate the application of this technique we provide a public Python package, called PyStacker.

10.Survey for Distant Stellar Aggregates in Galactic Disk: Detecting Two Thousand Star Clusters and Candidates, along with the Dwarf Galaxy IC10

Authors:Zhihong He, Yangping Luo, Kun Wang, Anbing Ren, Liming Peng, Qian Cui, Xiaochen Liu, Qingquan Jiang

Abstract: Despite having data for over 10^9 stars from Gaia, only less than 10^4 star clusters and candidates have been discovered. Particularly, distant star clusters are rarely identified, due to the challenges posed by heavy extinction and great distance. However, Gaia data has continued to improve, enabling even fainter cluster members to be distinguished from field stars. In this work, we will introduce a star cluster search method based on the DBSCAN algorithm; we have made improvements to make it better suited for identifying clusters on dimmer and more distant stars. After removing member stars of known Gaia-based clusters, we have identified 2086 objects with |b|<10 deg, of which 1488 are highly reliable open star clusters, along with 569 candidates, 28 globular cluster candidates and 1 irregular galaxy IC 10 at low Galactic latitudes. We found that the proper motion of IC10 is similar yet slightly different from the water maser observations, which is an important result for the comparison with Gaia and VLBA. Besides, when compared with the star clusters appearing in Gaia DR2/EDR3, we have found nearly three times as many new objects above a distance of 5 kpc, including hundreds of them above Av > 5 mag. And it has enabled us to detect a higher number of old clusters, over a billion years old, that are difficult to detect due to observational limitations. Our findings significantly expand the remote cluster sample and enhance our understanding of the limits of Gaia DR3 data in stellar aggregates research. The full figure set for 2085 clusters can be seen in \url{}

1.Ionized gas metallicity of the strong [OIII]λ emission-line compact galaxies in the LAMOST survey

Authors:Siqi Liu, A-Li Luo, Wei Zhang, Xiao Kong, Yong-Heng Zhao

Abstract: This article reports a sample of 1830 strong [O III] {\lambda}5007 emission-line compact galaxies discovered with the LAMOST spectroscopic survey and the photometric catalog of SDSS. We newly identify 402 spectra of 346 strong [O III]{\lambda}5007 emission-line compact galaxies by finding compact isolated point sources. Combined with the samples in our previous work (Liu et al. 2022), this returns a sample of 1830 unique strong [O III]{\lambda}5007 emission-line compact galaxies with 2033 spectra of z <= 0.53. For the sources with 2{\sigma} [OIII]{\lambda}4363 detections, we calculate the gas-phase metallicity with the direct-Te method, and verify that the strong-line metallicity diagnostics calibrated with the direct-Te method also applies to this sample. The strong [O III]{\lambda}5007 emission-line compact galaxies fall below several Te-calibrated mass-metallicity relations. The N/O measurements of the strong [O iii]{\lambda}5007 emission-line compact galaxies mainly locate at a plateau at low metallicity, indicating the product of primary nucleosynthesis. The Ne3O2 and O32 relation follows a tight linear relation with no redshift evolution. The Ne3O2 anti-correlates with the stellar mass, and at fixed stellar mass the Ne3O2 increase with the redshift. Eight sources with asymmetric [O III]{\lambda}5007 emission-line profiles have been identified, however with no [O III]{\lambda}4363 detection, which proves the rich metal content and complex ionized gas kinematics within the galaxies. Higher-resolution spectroscopy will be necessary to identify the ionized gas components in detail.

2.A Geometric Calibration of the Tip of the Red Giant Branch in the Milky Way using Gaia DR3

Authors:M. Dixon, J. Mould, C. Flynn, E. N. Taylor, C. Lidman, A. R. Duffy

Abstract: We use the latest parallaxes measurements from Gaia DR3 to obtain a geometric calibration of the tip of the red giant branch (TRGB) in Cousins $I$ magnitudes as a standard candle for cosmology. We utilise the following surveys: SkyMapper DR3, APASS DR9, ATLAS Refcat2, and Gaia DR3 synthetic photometry to obtain multiple zero-point calibrations of the TRGB magnitude, $M_{I}^{TRGB}$. Our sample contains Milky Way halo stars at high galactic latitudes ($|b| > 36$) where the impact of metallicity, dust, and crowding are minimised. The magnitude of the TRGB is identified using Sobel edge detection, but this approach introduced a systematic offset. To address this issue, we utilised simulations with PARSEC isochrones and showed how to calibrate and remove this bias. Applying our method within the colour range where the slope of the TRGB is relatively flat for metal-poor halo stars (1.55 $<$ $(BP-RP)$ $<$ 2.25), we find a weighted average $M_{I}^{TRGB} = -4.042 \pm 0.041$ (stat) $\pm0.031$ (sys) mag. A geometric calibration of the Milky Way TRGB has the benefit of being independent of other distance indicators and will help probe systematics in the local distance ladder, leading to improved measurements of the Hubble constant.

3.A twisted and precessing Cepheid warp in the outer Milky Way disc

Authors:Walter Dehnen, Marcin Semczuk, Ralph Schönrich

Abstract: We examine the Galactic warp in a sample of all classical Cepheids with Gaia DR3 radial velocity. In each radial bin, we determine (1) the inclined plane normal to the mean orbital angular momentum of the stars and (2) that best fitting their positions. We find no warping inside $R\approx 11$ kpc; for larger $R$ the disc is increasingly inclined, reaching $i\sim 3^{\circ}$ at $R \ge 14$ kpc. With larger $R$ the azimuth of the warp's ascending node shifts from $\varphi_{\mathrm{lon}}\approx-15^\circ$ at 11 kpc by about $14^{\circ}$/kpc in the direction of Galactic rotation, implying a leading spiral of nodes, the general behaviour of warped galaxies. From the method of fitting planes to the positions we also obtain $\dot{\varphi}_{\mathrm{lon}}$ and find prograde precession of $\dot{\varphi}_{\mathrm{lon}} \sim 12$ km/s/kpc at 12 kpc decreasing to $\sim 6$ km/s/kpc at 14 kpc and beyond. This would unwind the leading spiral of nodes in $\sim 100$ Myr, suggesting that our instantaneous measurements of $\dot{\varphi}_{\mathrm{lon}}$ reflect transient behaviour. This is consistent with existing simulations, which show oscillations in $\dot{\varphi}_{\mathrm{lon}}$ overlaying a long-term retrograde differential precession which generates the leading spiral of nodes.

4.Dynamical modelling of ATLAS$^{\rm 3D}$ galaxies

Authors:Sabine Thater, Prashin Jethwa, Edward J. Lilley, Alice Zocchi, Giulia Santucci, Glenn van de Ven

Abstract: Triaxial dynamical models of massive galaxies observed in the ATLAS3D project can provide new insights into the complex evolutionary processes that shape galaxies. The ATLAS3D survey is ideal as the sample comprises a good mix of fast and slow rotators with vastly different mass assembly histories. We present a detailed dynamical study with our triaxial modelling code DYNAMITE, which models galaxies as a superposition of their stellar orbits. The models allow us to constrain the intrinsic shape of the stellar component, the distributions of the visible and invisible matter and the orbit distribution in these nearby early-type galaxies and to relate it with different evolutionary scenarios. Triaxial modelling is essential for these galaxies to understand their complex kinematical features.

5.Probing $z \gtrsim 6$ massive black holes with gravitational waves

Authors:Srija Chakraborty, Simona Gallerani, Tommaso Zana, Alberto Sesana, Milena Valentini, David Izquierdo-Villalba, Fabio Di Mascia, Fabio Vito, Paramita Barai

Abstract: We investigate the coalescence of massive black hole ($M_{\rm BH}\gtrsim 10^{6}~\rm M_{\odot}$) binaries (MBHBs) at $6<z<10$ by adopting a suite of cosmological hydrodynamical simulations of galaxy formation, zoomed-in on biased ($ >3 \sigma$) overdense regions ($M_h\sim 10^{12}~\rm M_{\odot}$ dark matter halos at $z = 6$) of the Universe. We first analyse the impact of different resolutions and AGN feedback prescriptions on the merger rate, assuming instantaneous mergers. Then, we compute the halo bias correction factor due to the overdense simulated region. Our simulations predict merger rates that range between 3 - 15 $\rm yr^{-1}$ at $z\sim 6$, depending on the run considered, and after correcting for a bias factor of $\sim 20-30$. For our fiducial model, we further consider the effect of delay in the MBHB coalescence due to dynamical friction. We find that 83 per cent of MBHBs will merge within the Hubble time, and 21 per cent within 1 Gyr, namely the age of the Universe at $z > 6$. We finally compute the expected properties of the gravitational wave (GW) signals and find the fraction of LISA detectable events with high signal-to-noise ratio (SNR $>$ 5) to range between 66-69 per cent. However, identifying the electro-magnetic counterpart of these events remains challenging due to the poor LISA sky localization that, for the loudest signals ($\mathcal M_c\sim 10^6~\rm M_{\odot}$ at $z=6$), is around 10 $\rm deg^2$.

6.Strömgren photometric metallicity of the Small Magellanic Cloud stars using Gaia DR3-XP spectra

Authors:Abinaya O. Omkumar, Smitha Subramanian, Maria-Rosa L. Cioni, Jos de Bruijne

Abstract: Observational studies have identified several sub-structures in different regions of the Magellanic Clouds, the nearest pair of interacting dwarf satellites of the Milky Way. By studying the metallicity of the sources in these sub-structures, we aim to shed light on the possible origin of these sub-structures. Spectroscopic metallicities exist only for a few thousand sources, mostly giant stars located in specific regions of the galaxies. These metallicities come from different instruments at various spectral resolutions, and systematic uncertainties hamper comparisons and draw firm conclusions about their origin. The third data release of \textit{Gaia} has provided us with $\sim$ 0.17 million XP spectra of the different stellar populations in the SMC alone as faint as $\sim$ 18 mags in the G band, which are spread across $\sim$ 10$^\circ$ from the SMC centre. We aim to determine the metallicities of these sources based on synthetic Str\"{o}mgren photometry derived from XP spectra and produce a high-resolution metallicity map of the SMC. Our metallicity gradient estimate of the SMC turns out to be --0.062 $\pm$ 0.009 dex/deg. This is comparable with the previous estimates, which also validate our method of metallicity estimation. We aim to apply this method to other stellar populations and to the LMC to create a high-resolution metallicity map of the Magellanic Clouds.

7.The Three Hundred Project: the evolution of physical baryon profiles

Authors:Qingyang Li, Weiguang Cui, Xiaohu Yang, Romeel Dave, Elena Rasia, Stefano Borgani, Meneghetti Massimo, Alexander Knebe, Klaus Dolag, Jack Sayers

Abstract: The distribution of baryons provides a significant way to understand the formation of galaxy clusters by revealing the details of its internal structure and changes over time. In this paper, we present theoretical studies on the scaled profiles of physical properties associated with the baryonic components, including gas density, temperature, metallicity, pressure and entropy as well as stellar mass, metallicity and satellite galaxy number density in galaxy clusters from $z=4$ to $z=0$ by tracking their progenitors. These mass-complete simulated galaxy clusters are coming from THE THREE HUNDRED with two runs: GIZMO-SIMBA and Gadget-X. Through comparisons between the two simulations, and with observed profiles which are generally available at low redshift, we find that (1) the agreements between the two runs and observations are mostly at outer radii $r \gtrsim 0.3r_{500}$, in line with the self-similarity assumption. While Gadget-X shows better agreements with the observed gas profiles in the central regions compared to GIZMO-SIMBA; (2) the evolution trends are generally consistent between the two simulations with slightly better consistency at outer radii. In detail, the gas density profile shows less discrepancy than the temperature and entropy profiles at high redshift. The differences in the cluster centre and gas properties imply different behaviours of the AGN models between Gadget-X and GIZMO-SIMBA, with the latter, maybe too strong for this cluster simulation. The high-redshift difference may be caused by the star formation and feedback models or hydrodynamics treatment, which requires observation constraints and understanding.

1.QUIJOTE Scientific Results -- XVII. Studying the Anomalous Microwave Emission in the Andromeda Galaxy with QUIJOTE-MFI

Authors:M. Fernández-Torreiro, R. T. Génova-Santos, J. A. Rubiño-Martín, C. H. López-Caraballo, M. W. Peel, C. Arce-Tord, R. Rebolo, E. Artal, M. Ashdown, R. B. Barreiro, F. J. Casas, E. de la Hoz, F. Guidi, D. Herranz, R. Hoyland, A. Lasenby, E. Martínez-Gonzalez, L. Piccirillo, F. Poidevin, B. Ruiz-Granados, D. Tramonte, F. Vansyngel, P. Vielva, R. A. Watson

Abstract: The Andromeda Galaxy (M31) is the Local Group galaxy that is most similar to the Milky Way (MW). The similarities between the two galaxies make M31 useful for studying integrated properties common to spiral galaxies. We use the data from the recent QUIJOTE-MFI Wide Survey, together with new raster observations focused on M31, to study its integrated emission. The addition of raster data improves the sensitivity of QUIJOTE-MFI maps by a factor greater than 3. Our main interest is to confirm if anomalous microwave emission (AME) is present in M31, as previous studies have suggested. To do so, we built the integrated spectral energy distribution of M31 between 0.408 and 3000 GHz. We then performed a component separation analysis taking into account synchrotron, free-free, AME and thermal dust components. AME in M31 is modelled as a log-normal distribution with maximum amplitude, $A_{\rm AME}$, equal to $1.06\pm0.30$ Jy. It peaks at $\nu_{\rm AME}=17.28\pm3.08$ GHz with a width of $W_{\rm AME}=0.57\pm0.15$. Both the Akaike and Bayesian Information Criteria find the model without AME to be less than 1 % as probable as the one taking AME into consideration, thus strongly favouring the presence of AME in M31. We find that the AME emissivity in M31 is $\epsilon_{\rm AME}^{\rm 28.4\,GHz}=9.1\pm2.9$ $\mu$K/(MJy/sr), similar to that computed for the MW. We also provide the first upper limits for the AME polarization fraction in an extragalactic object. M31 remains the only galaxy where an AME measurement has been made of its integrated spectrum.

2.Examining transitional galaxies to understand the role of clusters and their dynamical status in galaxy quenching

Authors:Douglas Brambila, Paulo A. A. Lopes, André L. B. Ribeiro, Arianna Cortesi

Abstract: In this work, we consider four different galaxy populations and two distinct global environments in the local Universe (z $\leq 0.11$) to investigate the evolution of transitional galaxies (such as star-forming spheroids and passive discs) across different environments. Our sample is composed of 3,899 galaxies within the R$_{200}$ radius of 231 clusters and 11,460 field galaxies. We also investigate the impact of the cluster's dynamic state, as well as the galaxy's location in the projected phase space diagram (PPS). We found that although the cluster environment as a whole influences galaxy evolution, the cluster dynamical state does not. Furthermore, star-forming galaxies represent recent cluster arrivals in comparison to passive galaxies (especially in the case of early-types). Among the ETGs, we find that the D$_n(4000)$ and H$_\delta$ parameters indicate a smooth transition between the subpopulations. In particular, for the SF-ETGs, we detect a significant difference between field and cluster galaxies, as a function of stellar mass, for objects with Log $M_*$/M$_{\odot} > 10.5$. Analyzing the color gradient, the results point toward a picture where field galaxies are more likely to follow the monolithic scenario, while the cluster galaxies the hierarchical scenario. In particular, if we split the ETGs into lenticulars and ellipticals, we find that the steeper color gradients are more common for the lenticulars. Finally, our results indicate the need for galaxy pre-processing in smaller groups, before entering clusters.

3.Probing bursty star formation by cross-correlating extragalactic background light and galaxy surveys

Authors:Guochao Sun, Adam Lidz, Andreas L. Faisst, Claude-André Faucher-Giguère

Abstract: Understanding the star formation rate (SFR) variability and how it depends on physical properties of galaxies is important for developing and testing the theory of galaxy formation. We investigate how statistical measurements of the extragalactic background light (EBL) can shed light on this topic and complement traditional methods based on observations of individual galaxies. Using semi-empirical models of galaxy evolution and SFR indicators sensitive to different star formation timescales (e.g., H$\alpha$ and UV continuum luminosities), we show that the SFR variability, quantified by the joint probability distribution of the SFR indicators (i.e., the bivariate conditional luminosity function), can be characterized as a function of galaxy mass and redshift through the cross-correlation between deep, near-infrared maps of the EBL and galaxy distributions. As an example, we consider combining upcoming SPHEREx maps of the EBL with galaxy samples from Rubin/LSST. We demonstrate that their cross-correlation over a sky fraction of $f_\mathrm{sky}\sim0.5$ can constrain the joint SFR indicator distribution at high significance up to $z\sim2.5$ for mass-complete samples of galaxies down to $M_{*}\sim10^9\,M_{\odot}$. These constraints not only allow models of different SFR variability to be distinguished, but also provide unique opportunities to investigate physical mechanisms that require large number statistics such as environmental effects. The cross-correlations investigated illustrate the power of combining cosmological surveys to extract information inaccessible from each data set alone, while the large galaxy populations probed capture ensemble-averaged properties beyond the reach of targeted observations towards individual galaxies.

1.Large-scale Velocity-coherent Filaments in the SEDIGISM Survey: Association with Spiral Arms and Fraction of Dense Gas

Authors:Y. Ge, K. Wang, A. Duarte-Cabral, A. R. Pettitt, C. L. Dobbs, Á. Sánchez-Monge, K. R. Neralwar, J. S. Urquhart, D. Colombo, E. Durán-Camacho, H. Beuther, L. Bronfman, A. J. Rigby, D. Eden, S. Neupane, P. Barnes, T. Henning, A. Y. Yang

Abstract: Context. Filamentary structures in the interstellar medium are closely related to star formation. Dense gas mass fraction (DGMF) or clump formation efficiency in large-scale filaments possibly determine their hosting star formation activities. Aims. We aim to automatically identify large-scale filaments, characterize them, investigate their association with Galactic structures, and study their DGMFs. Methods. We use a modified minimum spanning tree (MST) algorithm to chain parsec-scale 13CO clumps previously extracted from the SEDIGISM (Structure, Excitation, and Dynamics of the Inner Galactic InterStellar Medium) survey. The MST connects nodes in a graph such that the sum of edge lengths is minimum. Modified MST also ensures velocity coherence between nodes, so the identified filaments are coherent in position-position-velocity (PPV) space. Results. We generate a catalog of 88 large-scale ($>10pc$) filaments in the inner Galactic plane (with $-60^\circ < l < 18^\circ and $|b| < 0.5^\circ$). These SEDIGISM filaments are larger and less dense than MST filaments previously identified from the BGPS and ATLASGAL surveys. We find that eight of the filaments run along spiral arms and can be regarded as "bones" of the Milky Way. We also find three bones associated with the Local Spur in PPV space. By compiling 168 large-scale filaments with available DGMF across the Galaxy, an order of magnitude more than previously investigated, we find that DGMFs do not correlate with Galactic location, but bones have higher DGMFs than other filaments.

2.GMP-selected dual and lensed AGNs: selection function and classification based on near-IR colors and resolved spectra from VLT/ERIS, KECK/OSIRIS, and LBT/LUCI

Authors:F. Mannucci, M. Scialpi, A. Ciurlo, S. Yeh, C. Marconcini, G. Tozzi, G. Cresci, A. Marconi, A. Amiri, F. Belfiore, S. Carniani, C. Cicone, E. Nardini, E. Pancino, K. Rubinur, P. Severgnini, L. Ulivi, G. Venturi, C. Vignali, M. Volonteri, E. Pinna, F. Rossi, A. Puglisi, G. Agapito, C. Plantet, E. Ghose, L. Carbonaro, M. Xompero, P. Grani, S. Esposito, J. Power, J. C. Guerra Ramon, M. Lefebvre, A. Cavallaro, R. Davies, A. Riccardi, M. Macintosh, W. Taylor, M. Dolci, A. Baruffolo, H. Feuchtgruber, K. Kravchenko, C. Rau, E. Sturm, E. Wiezorrek, Y. Dallilar, M. Kenworthy

Abstract: The Gaia-Multi-Peak (GMP) technique can identify large numbers of dual or lensed active galactic nuclei (AGN) candidates at sub-arcsec separation, allowing us to study both multiple super-massive black holes (SMBH) in the same galaxy and rare, compact lensed systems. The observed samples can be used to test the predictions of the models of SMBH merging once 1) the selection function of the GMP technique is known, and 2) each system has been classified as dual AGN, lensed AGN, or AGN/star alignment. Here we show that the GMP selection is very efficient for separations above 0.15" when the secondary (fainter) object has magnitude G<20.5. We present the spectroscopic classification of five GMP candidates using VLT/ERIS and Keck/OSIRIS, and compare them with the classifications obtained from: a) the near-IR colors of 7 systems obtained with LBT/LUCI, and b) the analysis of the total, spatially-unresolved spectra. We conclude that colors and integrated spectra can already provide reliable classifications of many systems. Finally, we summarize the 14 confirmed dual AGNs at z>0.5 selected by the GMP technique, and compare this sample with other such systems from the literature, concluding that GMP can provide a large number of confirmed dual AGNs at separations below 7 kpc.

3.The outer low-$α$ disc of the Milky Way -- I: evidence for the first pericentric passage of Sagittarius?

Authors:Payel Das, Yang Huang, Ioana Ciuca, Francesca Fragkoudi

Abstract: Phase-space data, chemistry, and ages together reveal a complex structure in the outer low-${\alpha}$ disc of the Milky Way. The age-vertical velocity dispersion profiles beyond the Solar Neighbourhood show a significant jump at 6 Gyr for stars beyond the Galactic plane. Stars older than 6 Gyr are significantly hotter than younger stars. The chemistry and age histograms reveal a bump at [Fe/H] = -0.5, [${\alpha}$/Fe] = 0.1, and an age of 7.2 Gyr in the outer disc. Finally, viewing the stars beyond 13.5 kpc in the age-metallicity plane reveals a faint streak just below this bump, towards lower metallicities at the same age. Given the uncertainty in age, we believe these features are linked and suggest a pericentric passage of a massive satellite 6 Gyr ago that heated pre-existing stars, led to a starburst in existing gas. New stars also formed from the metal-poorer infalling gas. The impulse approximation was used to characterise the interaction with a satellite, finding a mass of ~1e11 M$_{\odot}$, and a pericentric position between 12 and 16 kpc. The evidence points to an interaction with the Sagittarius dwarf galaxy, likely its first pericentric passage.

4.Post-Starburst Properties of Post-Merger Galaxies

Authors:Wenhao Li, Preethi Nair, Kate Rowlands, Karen Masters, David Stark, Niv Drory, Sara Ellison, Jimmy Irwin, Shobita Satyapal, Amy Jones, William Keel, Kavya Mukundan, Zachary Tu

Abstract: Post-starburst galaxies (PSBs) are transition galaxies showing evidence of recent rapid star formation quenching. To understand the role of galaxy mergers in triggering quenching, we investigate the incidence of PSBs and resolved PSB properties in post-merger galaxies using both SDSS single-fiber spectra and MaNGA resolved IFU spectra. We find post-mergers have a PSB excess of 10 - 20 times that relative to their control galaxies using single-fiber PSB diagnostics. A similar excess of ~ 19 times is also found in the fraction of central (C)PSBs and ring-like (R)PSBs in post-mergers using the resolved PSB diagnostic. However, 60% of the CPSBs + RPSBs in both post-mergers and control galaxies are missed by the single-fiber data. By visually inspecting the resolved PSB distribution, we find that the fraction of outside-in quenching is 7 times higher than inside-out quenching in PSBs in post-mergers while PSBs in control galaxies do not show large differences in these quenching directions. In addition, we find a marginal deficit of HI gas in PSBs relative to non-PSBs in post-mergers using the MaNGA-HI data. The excesses of PSBs in post-mergers suggest that mergers play an important role in triggering quenching. Resolved IFU spectra are important to recover the PSBs missed by single-fiber spectra. The excess of outside-in quenching relative to inside-out quenching in post-mergers suggests that AGN are not the dominant quenching mechanism in these galaxies, but that processes from the disk (gas inflows/consumption and stellar feedback) play a more important role.

5.Spectral age distribution for radio-loud active galaxies in the XMM-LSS field

Authors:Siddhant Pinjarkar, Martin J. Hardcastle, Jeremy J. Harwood, Dharam V. Lal, Peter W. Hatfield, Matt J. Jarvis, Zara Randriamanakoto, Imogen H. Whittam

Abstract: Jets of energetic particles, as seen in FR type-I and FR type-II sources, ejected from the center of Radio-Loud AGN affect the sources surrounding intracluster medium/intergalactic medium. Placing constraints on the age of such sources is important in order to measure the jet powers and determine the effects on feedback. To evaluate the age of these sources using spectral age models, we require high-resolution multi-wavelength data. The new sensitive and high-resolution MIGHTEE survey of the XMM-LSS field along with data from the Low Frequency Array (LOFAR) and the Giant Metrewave Radio Telescope (GMRT) provide data taken at different frequencies with similar resolution, which enables us to determine the spectral age distribution for radio loud AGN in the survey field. In this study we present a sample of 28 radio galaxies with their best fitting spectral age distribution analyzed using the Jaffe-Perola (JP) model on a pixel-by-pixel basis. Fits are generally good and objects in our sample show maximum ages within the range of 2.8 Myr to 115 Myr with a median of 8.71 Myr. High-resolution maps over a range of frequencies are required to observe detailed age distributions for small sources and high-sensitivity maps will be needed in order to observe fainter extended emission. We do not observe any correlation between the total physical size of the sources and their age and we speculate both dynamical models and the approach to spectral age analysis may need some modification to account for our observations.

1.Exploring connections between the VLBI and optical morphology of AGNs and their host galaxies

Authors:David Fernández Gil, Jeffrey A. Hodgson, Benjamin L'Huillier

Abstract: We analyse VLBI and optical images of AGNs and their host galaxies and look for statistical correlations between the shape and orientation of the galaxy and the direction of the jet. We utilise the Astrogeo catalogue, which has over 9000 VLBI sources, many of those with a clear core-jet like structure that allows for the jet position angle to be reliably determined. We then use the VLBI source positions to search for optical counterparts within various optical surveys. In order to parameterise the orientation and shape of the host galaxy, we fitted a Gaussian elliptical model to the optical image, taking the PSF into account. We check our own shape parameters from this fit against the ones provided by the optical surveys. As of yet, no clear correlation between the galaxy morphology and the jet direction is seen.

2.Detection of multiple phase space overdensities of GSE stars by orbit integration

Authors:WenboWu, GangZhao, JiangChang, Xiang-XiangXue, YuqinChen, ChengdongLi, Xianhao Ye, Chengqun Yang

Abstract: In N-body simulations, nearly radial mergers can form shell-like overdensities in the sky position and phase space ($r-v_r$) due to the combination of dynamical friction and tidal stripping. The merger event of Gaia-Sausage-Enceladus has provided a unique opportunity to study the shells in the phase space. To search for them, we integrate the orbits of 5949 GSE-related halo K giants from the LAMOST survey and record their positions at all time intervals in $r-v_r$ diagram. After the subtraction of a smoothed background, we find six significant and complete thin chevron-like overdensities. The apocenters $r_\mathrm{apo}$ of stars in the six chevrons are around 6.75, 12.75, 18.75, 25.25, 27.25, and 30.25 kpc. These chevrons reveal the multiple pile-ups of GSE stars at different apocenters. The application of a different Milky Way mass $M_\mathrm{vir}$ will change the opening angles of these chevrons, while leave their apocenters almost unchanged. By comparing with a recent study of the phase space overdensities of local halo stars from Gaia RVS survey, our results are more inclined to a medium $M_\mathrm{vir}$ of $10^{12}\,M_\odot$. The application of a non-axisymmetric Galactic potential with a steadily rotating bar has a blurring effect on the appearance of these chevron-like overdensities, especially for the chevrons with $r_\mathrm{apo} > 20$ kpc.

3.QUIJOTE scientific results -- X. Spatial variations of Anomalous Microwave Emission along the Galactic plane

Authors:M. Fernández-Torreiro, J. A. Rubiño-Martín, C. H. López-Caraballo, R. T. Génova-Santos, M. W. Peel, F. Guidi, S. E. Harper, E. Artal, M. Ashdown, R. B. Barreiro, F. J. Casas, E. de la Hoz, D. Herranz, R. Hoyland, A. Lasenby, E. Martínez-Gonzalez, L. Piccirillo, F. Poidevin, R. Rebolo, B. Ruiz-Granados, D. Tramonte, F. Vansyngel, P. Vielva, R. A. Watson

Abstract: Anomalous Microwave Emission (AME) is an important emission component between 10 and 60 GHz that is not yet fully understood. It seems to be ubiquituous in our Galaxy and is observed at a broad range of angular scales. Here we use the new QUIJOTE-MFI wide survey data at 11, 13, 17 and 19 GHz to constrain the AME in the Galactic plane ($|b|<10^\circ$) on degree scales. We built the spectral energy distribution between 0.408 and 3000 GHz for each of the 5309 0.9$^\circ$, pixels in the Galactic plane, and fitted a parametric model by considering five emission components: synchrotron, free-free, AME, thermal dust and CMB anisotropies. We show that not including QUIJOTE-MFI data points leads to the underestimation (up to 50 %) of the AME signal in favour of free-free emission. The parameters describing these components are then intercompared, looking for relations that help to understand AME physical processes. We find median values for the AME width, $W_{\rm AME}$, and for its peak frequency, $\nu_{\rm AME}$, respectively of $0.560^{+0.059}_{-0.050}$ and $20.7^{+2.0}_{-1.9}$ GHz, slightly in tension with current theoretical models. We find spatial variations throughout the Galactic plane for $\nu_{\rm AME}$, but only with reduced statistical significance. We report correlations of AME parameters with certain ISM properties, such as that between the AME emissivity (which shows variations with the Galactic longitude) and the interstellar radiation field, and that between the AME peak frequency and dust temperature. Finally, we discuss the implications of our results on the possible molecules responsible for AME.

4.Halo mass-observable proxy scaling relations and their dependencies on galaxy and group properties

Authors:Ziwen Zhang, Huiyuan Wang, Wentao Luo, Houjun Mo, Jun Zhang, Xiaohu Yang, Hao Li, Qinxun Li

Abstract: Based on the DECaLS shear catalog, we study the scaling relations between halo mass($M_{\rm h}$) and various proxies for SDSS central galaxies, including stellar mass($M_*$), stellar velocity dispersion($\sigma_*$), abundance matching halo mass($M_{\rm AM}$) and satellite velocity dispersion($\sigma_{\rm s}$), and their dependencies on galaxy and group properties. In general, they are all good proxies of $M_{\rm h}$, and their scaling relations are consistent with previous studies. We find that the $M_{\rm h}$-$M_*$ and $M_{\rm h}$-$\sigma_*$ relations depend strongly on group richness($N_{\rm sat}$), while the $M_{\rm h}$-$M_{\rm AM}$ and $M_{\rm h}$-$\sigma_{\rm s}$ relations are independent of it. Moreover, the dependence on star formation rate(SFR) is rather weak in the $M_{\rm h}$-$\sigma_*$ and $M_{\rm h}$-$\sigma_{\rm s}$ relations, but very prominent in the other two. $\sigma_{\rm s}$ is thus the best proxy among them, and its scaling relation is in good agreement with hydro-dynamical simulations. However, estimating $\sigma_{\rm s}$ accurately for individual groups/clusters is challenging because of interlopers and the requirement for sufficient satellites. We construct new proxies by combining $M_*$, $\sigma_*$, and $M_{\rm AM}$, and find the proxy with 30\% contribution from $M_{\rm AM}$ and 70\% from $\sigma_*$ can minimize the dependence on $N_{\rm sat}$ and SFR. We obtain the $M_{\rm h}$-supermassive black hole(SMBH) mass relation via the SMBH scaling relation and find indications for rapid and linear growth phases for SMBH. We also find that correlations among $M_{\rm h}$, $M_*$ and $\sigma_*$ change with $M_*$, indicating that different processes drive the growth of galaxies and SMBH at different stages.

1.A 3D physico-chemical model of a pre-stellar core. I. Environmental and structural impact on the distribution of CH$_3$OH and $c$-C$_3$H$_2$

Authors:S. S. Jensen, S. Spezzano, P. Caselli, T. Grassi, T. Haugbølle

Abstract: Pre-stellar cores represent the earliest stage of the star- and planet-formation process. By characterizing the physical and chemical structure of these cores we can establish the initial conditions for star and planet formation and determine to what degree the chemical composition of pre-stellar cores is inherited to the later stages. A 3D MHD model of a pre-stellar core embedded in a dynamic star-forming cloud is post-processed using sequentially continuum radiative transfer, a gas-grain chemical model, and a line-radiative transfer model. Results are analyzed and compared to observations of CH$_3$OH and $c$-C$_3$H$_2$ in L1544. Nine different chemical models are compared to the observations to determine which initial conditions are compatible with the observed chemical segregation in the prototypical pre-stellar core L1544. The model is able to reproduce several aspects of the observed chemical differentiation in L1544. Extended methanol emission is shifted towards colder and more shielded regions of the core envelope while $c$-C$_3$H$_2$ emission overlaps with the dust continuum, consistent with the observed chemical structure. Increasing the strength of the interstellar radiation field or the cosmic-ray ionization rate with respect to the typical values assumed in nearby star-forming regions leads to synthetic maps that are inconsistent with the observed chemical structure. Our model shows that the observed chemical dichotomy in L1544 can arise as a result of uneven illumination due to the asymmetrical structure of the 3D core and the environment within which the core has formed. This highlights the importance of the 3D structure at the core-cloud transition on the chemistry of pre-stellar cores.

2.ALMA 1.1mm Observations of a Conservative Sample of High Redshift Massive Quiescent Galaxies in SHELA

Authors:Katherine Chworowsky, Steven L. Finkelstein, Justin S. Spilker, Gene C. K. Leung, Micaela B. Bagley, Caitlin M. Casey, Caryl Gronwall, Shardha Jogee, Rebecca L. Larson, Casey Papovich, Rachel S. Somerville, Matthew Stevans, Isak G. B. Wold, L. Y. Aaron Yung

Abstract: We present a sample of 30 massive (log$(M_{\ast}/M_\odot) >11$) $z=3-5$ quiescent galaxies selected from the \textit{Spitzer-}HETDEX Exploratory Large Area (SHELA) Survey and observed at 1.1mm with Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations. These ALMA observations would detect even modest levels of dust-obscured star-formation, on order of $\sim 20 \ M_\odot \textrm{yr}^{-1}$ at $z\sim4$ at a $1\sigma$ level, allowing us to quantify the amount of contamination from dusty star-forming sources in our quiescent sample. Starting with a parent sample of candidate massive quiescent galaxies from the Stevans et al. 2021 v1 SHELA catalog, we use the Bayesian \textsc{Bagpipes} spectral energy distribution fitting code to derive robust stellar masses ($M_*$) and star-formation rates (SFRs) for these sources, and select a conservative sample of 36 candidate massive ($M_* > 10^{11}M_\odot$) quiescent galaxies, with specific SFRs at $>2\sigma$ below the star-forming main sequence at $z\sim4$. Based on ALMA imaging, six of these candidate quiescent galaxies have the presence of significant dust-obscured star-formation, thus were removed from our final sample. This implies a $\sim 17\%$ contamination rate from dusty star-forming galaxies with our selection criteria using the v1 SHELA catalog. This conservatively-selected quiescent galaxy sample at $z=3-5$ will provide excellent targets for future observations to better constrain how massive galaxies can both grow and shut-down their star-formation in a relatively short time period.

1.ALMA High-Level Data Products: Submillimetre counterparts of SDSS quasars in the ALMA footprint

Authors:A. Wong, E. Hatziminaoglou, A. Borkar, G. Popping, I. Pérez-Fournon, F. Poidevin, F. Stoehr, H. Messias

Abstract: The Atacama Large Millimetre/submillimetre Array (ALMA) is the world's most advanced radio interferometric facility, producing science data with an average rate of about 1 TB per day. After a process of calibration, imaging and quality assurance, the scientific data are stored in the ALMA Science Archive (ASA), along with the corresponding raw data, making the ASA an invaluable resource for original astronomical research. Due to their complexity, each ALMA data set has the potential for scientific results that go well beyond the ideas behind the original proposal that led to each observation. For this reason, the European ALMA Regional Centre initiated the High-Level Data Products initiative to develop science-oriented data products derived from data sets publicly available in the ASA, that go beyond the formal ALMA deliverables. The first instance of this initiative is the creation of a catalogue of submillimetre (submm) detections of Sloan Digital Sky Survey (SDSS) quasars from the SDSS Data Release 14 that lie in the aggregate ALMA footprint observed since ALMA Cycle 0. The ALMA fluxes are extracted in an automatic fashion, using the ALMA Data Mining Toolkit. All extractions above a signal-to-noise cut of 3.5 are considered, they have been visually inspected and the reliable detections are presented in a catalogue of 376 entries, corresponding to 275 unique quasars. Interesting targets found in the process, i.e. lensed or jetted quasars as well as quasars with nearby submm counterparts are highlighted, to facilitate further studies or potential follow up observations.

2.A high-redshift calibration of the [OI]-to-HI conversion factor in star-forming galaxies

Authors:Sophia N. Wilson, Kasper E. Heintz, Páll Jakobsson, Suzanne C. Madden, Darach Watson, Georgios Magdis, Francesco Valentino, Thomas R. Greve, David Vizgan

Abstract: The assembly and build-up of neutral atomic hydrogen (HI) in galaxies is one of the most fundamental processes in galaxy formation and evolution. Studying this process directly in the early universe is hindered by the weakness of the hyperfine 21-cm HI line transition, impeding direct detections and measurements of the HI gas masses ($M_{\rm HI}$). Here we present a new method to infer $M_{\rm HI}$ of high-redshift galaxies using neutral, atomic oxygen as a proxy. Specifically, we derive metallicity-dependent conversion factors relating the far-infrared [OI]-$63\mu$m and [OI]-$145\mu$m emission line luminosities and $M_{\rm HI}$ in star-forming galaxies at $z\approx 2-6$ using gamma-ray bursts (GRBs) as probes. We substantiate these results by observations of galaxies at $z\approx 0$ with direct measurements of $M_{\rm HI}$ and [OI]-$63\mu$m and [OI]-$145\mu$m in addition to hydrodynamical simulations at similar epochs. We find that the [OI]$_{\rm 63\mu m}$-to-HI and [OI]$_{\rm 145\mu m}$-to-HI conversion factors universally appears to be anti-correlated with the gas-phase metallicity. The high-redshift GRB measurements further predict a mean ratio of $L_{\rm [OI]-63\mu m} / L_{\rm [OI]-145\mu m}=1.55\pm 0.12$ and reveal generally less excited [CII]. The $z \approx 0$ galaxy sample also shows systematically higher $\beta_{\rm [OI]-63\mu m}$ and $\beta_{\rm [OI]-145\mu m}$ conversion factors than the GRB sample, indicating either suppressed [OI] emission in local galaxies or more extended, diffuse HI gas reservoirs traced by the HI 21-cm. Finally, we apply these empirical calibrations to the few high-redshift detections of [OI]-$63\mu$m and [OI]-$145\mu$m line transitions from the literature and further discuss the applicability of these conversion factors to probe the HI gas content in the dense, star-forming ISM of galaxies at $z\gtrsim 6$, well into the epoch of reionization.

3.More relaxed intracluster gas than galaxies in clusters in quasi-equilibrium

Authors:Z. S. Yuan, J. L. Han, H. Böhringer, Z. L. Wen, G. Chon

Abstract: During cluster mergers, the intracluster gas and member galaxies undergo dynamic evolution, but at different timescales and reach different states. We collect 24 galaxy clusters in quasi-equilibrium state as indicated by the X-ray image, and calculate the cluster orientations and three kinds of dynamical parameters, i.e., the normalized centroid offset, the sphere index and the ellipticity, for these clusters from the distributions of member galaxies and also the intracluster gas. We find consistent alignments for the orientations estimated from the two components. However, the three kinds of dynamical parameters indicated by member galaxies are systematically larger than those derived from the gas component, suggesting that the gas component is more relaxed than member galaxies. Differences of dynamical features between the intracluster gas and member galaxies are independent of cluster mass and concentration. We conclude that the intracluster gas reaches the dynamic equilibrium state earlier than the almost collisionless member galaxies.

4.Low-Temperature Kinetics for the N + NO reaction: Experiment Guides the Way

Authors:Kevin M. Hickson, Juan Carlos San Vicente Veliz, Debasish Koner, Markus Meuwly

Abstract: The reaction N(4S) + NO -> O(3P) + N2 plays a pivotal role in the conversion of atomic to molecular nitrogen in dense interstellar clouds and in the atmosphere. Here we report a joint experimental and computational investigation of the N + NO reaction with the aim of providing improved constraints on its low temperature reactivity. Thermal rates were measured over the 50 to 296 K range in a continuous supersonic flow reactor coupled with pulsed laser photolysis and laser induced fluorescence for the production and detection of N(4S) atoms, respectively. With decreasing temperature, the experimentally measured reaction rate was found to monotonously increase up to a value of (6.6 +- 1.3) x 10-11 cm3 s-1 at 50 K. To confirm this finding, quasi-classical trajectory simulations were carried out on a previously validated, full-dimensional potential energy surface (PES). However, around 50 K the computed rates decreased which required re-evaluation of the reactive PES in the long-range part due to a small spurious barrier with height 40 K in the entrance channel. By exploring different correction schemes the measured thermal rates can be adequately reproduced, displaying a clear negative temperature dependence over the entire temperature range. The possible astrochemical implications of an increased reaction rate at low temperature are also discussed.

5.Metal-poor stars observed with the Magellan Telescope. IV. Neutron-capture element signatures in 27 main-sequence stars

Authors:Mohammad K. Mardini, Anna Frebel, Leyatt Betre, Heather Jacobson, John E. Norris, Norbert Christlieb

Abstract: Based on high-resolution spectra obtained with Magellan/MIKE, we present a chemo-dynamical analysis for 27 near main-sequence turnoff metal-poor stars, including 20 stars analyzed for the first time. The sample spans a range in [Fe/H] from -2.5 to -3.6, with 44% having [Fe/H] <-2.9. We derived chemical abundances for 17 elements, including strontium and barium. We derive Li abundances for the sample, which are in good agreement with the ``Spite Plateau'' value. A dozen of stars are carbon-enhanced. The lighter elements (Z<30) generally agree well with those of other low-metallicity halo stars. This broadly indicates chemically homogeneous gas at the earliest times. Of the neutron-capture elements, we only detected strontium and barium. We used the [Sr/Ba] vs. [Ba/Fe] diagram to classify metal-poor stars into five populations based on their observed ratios. We find HE0232-3755 to be a likely main r-process star, and HE2214-6127 and HE2332-3039 to be limited-r stars. CS30302-145, HE2045-5057, and CD-24 17504 plausibly originated in long-disrupted early dwarf galaxies as evidenced by their [Sr/Ba] and [Ba/Fe] ratios. We also find that the derived [Sr/H] and [Ba/H] values for CD-24 17504 are not inconsistent with the predicted yields of the s-process in massive rotating low-metallicity stars models. Further theoretical explorations will be helpful to better understand the earliest mechanisms and time scales of heavy element production for comparison with these and other observational abundance data. Finally, we investigate the orbital histories of our sample stars. Most display halo-like kinematics although three stars (CS29504-018, HE0223-2814, and HE2133-0421) appear to be disk-like in nature. This confirms the extragalactic origin for CS30302-145, HE2045-5057, and, in particular, CD-24 17504 which likely originated from a small accreted stellar system as one of the oldest stars.

6.HSC-CLAUDS survey: The star formation rate functions since z ~ 2 and comparison with hydrodynamical simulations

Authors:V. Picouet, S. Arnouts, E. Le Floch, T. Moutard, K. Kraljic, O. Ilbert, M. Sawicki, G. Desprez, C. Laigle, D. Schiminovich, S. de la Torre, S. Gwyn, H. J. McCracken, Y. Dubois, R. Davé, S. Toft, J. R. Weaver, M. Shuntov, O. B. Kauffmann

Abstract: Star formation rate functions (SFRFs) give an instantaneous view of the distribution of star formation rates (SFRs) in galaxies at different epochs. They are a complementary and more stringent test for models than the galaxy stellar mass function, which gives an integrated view of the past star formation activity. However, the exploration of SFRFs has been limited thus far due to difficulties in assessing the SFR from observed quantities and probing the SFRF over a wide range of SFRs. We overcome these limitations thanks to an original method that predicts the infrared luminosity from the rest-frame UV/optical color of a galaxy and then its SFR over a wide range of stellar masses and redshifts. We applied this technique to the deep imaging survey HSC-CLAUDS combined with near-infrared and UV photometry. We provide the first SFR functions with reliable measurements in the high- and low-SFR regimes up to $z=2$ and compare our results with previous observations and four state-of-the-art hydrodynamical simulations.

7.The Dragonfly Galaxy. III. Jet-brightening of a High-redshift Radio Source Caught in a Violent Merger of Disk Galaxies

Authors:Sophie Lebowitz Univ. Arizona Ohio State Univ, Bjorn Emonts NRAO, Donald M. Terndrup Ohio State Univ, Joseph N. Burchett New Mexico State Univ, J. Xavier Prochaska UC Santa Cruz Univ. Tokyo NAOJ, Guillaume Drouart Curtin Univ, Montserrat Villar-Martin CAB/CSIC-INTA, Matthew Lehnert CRAL/Univ. Lyon, Carlos De Breuck ESO, Joel Vernet ESO, Katherine Alatalo STScI Johns Hopkins Univ

Abstract: The Dragonfly Galaxy (MRC 0152-209), the most infrared-luminous radio galaxy at redshift z~2, is a merger system containing a powerful radio source and large displacements of gas. We present kpc-resolution data from ALMA and the VLA of carbon monoxide (6-5), dust, and synchrotron continuum, combined with Keck integral-field spectroscopy. We find that the Dragonfly consists of two galaxies with rotating disks that are in the early phase of merging. The radio jet originates from the northern galaxy and brightens when it hits the disk of the southern galaxy. The Dragonfly Galaxy therefore likely appears as a powerful radio galaxy because its flux is boosted into the regime of high-z radio galaxies by the jet-disk interaction. We also find a molecular outflow of (1100 $\pm$ 550) M$_{\odot}$/yr associated with the radio host galaxy, but not with the radio hot-spot or southern galaxy, which is the galaxy that hosts the bulk of the star formation. Gravitational effects of the merger drive a slower and longer lived mass displacement at a rate of (170 $\pm$ 40) M$_{\odot}$/yr, but this tidal debris contain at least as much molecular gas mass as the much faster outflow, namely M(H2) = (3 $\pm$ 1) x 10$^9$ (alpha(CO)/0.8) M$_{\odot}$. This suggests that both the AGN-driven outflow and mass transfer due to tidal effects are important in the evolution of the Dragonfly system. The Keck data show Ly$\alpha$ emission spread across 100 kpc, and CIV and HeII emission across 35 kpc, confirming the presence of a metal-rich and extended circumgalactic medium previously detected in CO(1-0).

8.Measuring Dust Attenuation Curves of SINGS/KINGFISH Galaxies Using Swift/UVOT Photometry

Authors:Alexander Belles, Marjorie Decleir, William P. Bowman, Lea M. Z. Hagen, Caryl Gronwall, Michael H. Siegel

Abstract: We present Swift/Ultraviolet Optical Telescope (UVOT) integrated light photometry of the Spitzer Infrared Nearby Galaxies Survey (SINGS) and the Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel (KINGFISH) samples of nearby galaxies. Combining the Swift/UVOT data with archival photometry, we investigate a variety of dust attenuation curves derived using MCSED, a flexible spectral energy distribution fitting code. We fit the panchromatic data using three different star formation history (SFH) parameterizations: a decaying exponential, a double power law, and a piecewise function with breaks at physically motivated ages. We find that the average attenuation law of the sample changes slightly based on the SFH assumed. Specifically, the exponential SFH leads to the shallowest attenuation curves. Using simulated data, we also find the exponential SFH fails to outperform the more complex SFHs. Finally, we find a systematic offset in the derived bump strength between SED fits with and without UVOT data, where the inclusion of UVOT data leads to smaller bump strengths, highlighting the importance of the UVOT data. This discrepancy is not seen in fits to mock photometry. Understanding dust attenuation in the local universe is key to understanding high redshift objects where rest-frame far-infrared data is unavailable.

1.Radiation pressure acting on the neutral He atoms in the Heliosphere

Authors:Izabela Kowalska-Leszczynska, Marzena A. Kubiak, Maciej Bzowski

Abstract: The Interstellar Neutral Helium (ISN He) is an important source of information on the physical state of the Local Interstellar Medium. Radiation pressure acting on the neutral helium atoms in the heliosphere has always been neglected, its effect has been considered insignificant compared to gravitational force. The most advanced numerical models of ISN He take into account more and more subtle effects, therefore it is important to check if the effect of radiation pressure is still negligible. In this paper, we use the most up-to-date version of the Warsaw Test Particle Model (WTPM) to calculate the expected helium distribution in the heliosphere, and simulate the flux of ISN He observed by the Interstellar Boundary Explorer (IBEX) and in the future by the Interstellar Mapping and Acceleration Probe (IMAP). We compare results calculated with and without radiation pressure during low and high solar activity. The results show that in the analysis of IBEX-Lo observations the radiation pressure acting on typical helium causes flux differences at a level of 1-4% and is comparable to the observational errors. For the more sensitive IMAP-Lo instrument, there are some regions in the considered observations configurations where radiation pressure causes potentially statistically significant changes in the calculated fluxes. The effect can be up to 9% for the indirect beam and is likely to be higher than the estimated errors. Therefore, we claim that in the future analysis of the IMAP-Lo observations radiation pressure acting on ISN He should be considered.

2.Precise Masses, Ages of ~1.0 million RGB and RC stars observed by the LAMOST

Authors:Chun Wang, Yang Huang, Yutao Zhou, Huawei Zhang

Abstract: We construct a catalogue of stellar masses and ages for 696,680 red giant branch (RGB) stars, 180,436 primary red clump (RC) stars, and 120,907 secondary RC stars selected from the LAMOST\,DR8. The RGBs, primary RCs, and secondary RCs are identified with the large frequency spacing ($\Delta \nu$) and period spacing ($\Delta P$), estimated from the LAMOST spectra with spectral SNRs $> 10$ by the neural network method supervised with the seismologic information from LAMOST-Kepler sample stars. The purity and completeness of both RGB and RC samples are better than 95\% and 90\%, respectively. The mass and age of RGBs and RCs are determined again with the neural network method by taking the LAMOST-Kepler giant stars as the training set. The typical uncertainties of stellar mass and age are, respectively, 10\% and 30\% for the RGB stellar sample. For RCs, the typical uncertainties of stellar mass and age are 9\% and 24\%, respectively. The RGB and RC stellar samples cover a large volume of the Milky Way (5 $< R < 20$\,kpc and $|Z| <$\,5\,kpc), which are valuable data sets for various Galactic studies.

3.Radial velocities and stellar population properties of 56 MATLAS dwarf galaxies observed with MUSE

Authors:Nick Heesters, Oliver Müller, Francine R. Marleau, Pierre-Alain Duc, Rubén Sánchez-Janssen, Mélina Poulain, Rebecca Habas, Sungsoon Lim, Patrick R. Durrell

Abstract: Dwarf galaxies have been extensively studied in the Local Group, in nearby groups, and selected clusters, giving us a robust picture of their global stellar and dynamical properties in particular locations in the Universe. Intense study of these properties has revealed correlations between them, including the well known universal stellar mass-metallicity relation. However, since dwarfs play a role in a vast range of different environments, much can be learned about galaxy formation and evolution through extending the study of these objects to various locations. We present MUSE spectroscopy of a sample of 56 dwarf galaxies as a follow-up to the MATLAS survey in low-to-moderate density environments beyond the Local Volume. The dwarfs have stellar masses in the range of $M_{*}/M_{\odot}$ = 10$^{6.1}$-10$^{9.4}$ and show a distance range of D = 14-148 Mpc, the majority (75%) of which are located in the range targeted by the MATLAS survey (10-45 Mpc). We thus report a 75% (79% for dwarf ellipticals) success rate for the semi-automatic identification of dwarf galaxies in the MATLAS survey on the here presented subsample. Using pPXF full spectrum fitting, we determine their line-of-sight velocity and can match the majority of them with their massive host galaxy. Close inspection of their spectra reveals that ~30% show clear emission lines and thus star formation activity. We estimate their stellar population properties (age and metallicity) and compare our results with other works investigating Local Volume and cluster dwarf galaxies. We find that the dwarf galaxies presented in this work show a systematic offset from the stellar mass-metallicity relation towards lower metallicities at the same stellar mass. A similar deviation is present in other works in the stellar mass range probed in this work and might be attributed to the use of different methodologies for deriving the metallicity.

4.First evidence of multi-iron sub-populations in the Bulge Fossil Fragment candidate Liller 1

Authors:Chiara Crociati, Elena Valenti, Francesco R. Ferraro, Cristina Pallanca, Barbara Lanzoni, Mario Cadelano, Cristiano Fanelli, Livia Origlia, Emanuele Dalessandro, Alessio Mucciarelli, R. Michael Rich

Abstract: In the context of a project aimed at characterizing the properties of the so-called Bulge Fossil Fragments (the fossil remnants of the bulge formation epoch), here we present the first determination of the metallicity distribution of Liller 1. For a sample of 64 individual member stars we used ESO- MUSE spectra to measure the equivalent width of the CaII triplet and then derive the iron abundance. To test the validity of the adopted calibration in the metal-rich regime, the procedure was first applied to three reference bulge globular clusters (NGC 6569, NGC 6440, and NGC 6528). In all the three cases, we found single-component iron distributions, with abundance values fully in agreement with those reported in the literature. The application of the same methodology to Liller 1 yielded, instead, a clear bimodal iron distribution, with a sub-solar component at $\text{[Fe/H]}= -0.48\,$dex ($\sigma = 0.22$) and a super-solar component at $\text{[Fe/H]}= +0.26\,$dex ($\sigma = 0.17$). The latter is found to be significantly more centrally concentrated than the metal-poor population, as expected in a self-enrichment scenario and in agreement with what found in another bulge system, Terzan 5. The obtained metallicity distribution is astonishingly similar to that predicted by the reconstructed star formation history of Liller 1, which is characterized by three main bursts and a low, but constant, activity of star formation over the entire lifetime. These findings provide further support to the possibility that, similar to Terzan 5, also Liller 1 is a Bulge Fossil Fragment.

5.${\rm H_2CN}$/${\rm H_2NC}$ abundance ratio: a new potential temperature tracer for the interstellar medium

Authors:David San Andrés Centro de Astrobiología Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain, Laura Colzi Centro de Astrobiología, Víctor M. Rivilla Centro de Astrobiología, Juan García de la Concepción Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain IACYS-Unidad de Química Verde y Desarrollo Sostenible, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain, Mattia Melosso Scuola Superiore Meridionale, Naples, Italy, Jesús Martín-Pintado Centro de Astrobiología, Izaskun Jiménez-Serra Centro de Astrobiología, Shaoshan Zeng Star and Planet Formation Laboratory, Cluster for Pioneering Research, RIKEN, Hirosawa, Wako, Saitama, Japan, Sergio Martín European Southern Observatory, Vitacura, Santiago, Chile Joint ALMA Observatory, Vitacura, Santiago, Chile, Miguel A. Requena-Torres University of Maryland, College Park, USA Department of Physics, Astronomy and Geosciences, Towson University, USA

Abstract: The ${\rm H_2NC}$ radical is the high-energy metastable isomer of ${\rm H_2CN}$ radical, which has been recently detected for the first time in the interstellar medium towards a handful of cold galactic sources, besides a warm galaxy in front of the PKS 1830-211 quasar. These detections have shown that the ${\rm H_2CN}$/${\rm H_2NC}$ isomeric ratio, likewise the HCN/HNC ratio, might increase with the kinetic temperature ($T_{\rm kin}$), but the shortage of them in warm sources still prevents us to confirm this hypothesis and shed light about their chemistry. In this work, we present the first detection of ${\rm H_2CN}$ and ${\rm H_2NC}$ towards a warm galactic source, the G+0.693-0.027 molecular cloud (with $T_{\rm kin} > 70 \, {\rm K}$), using IRAM 30m observations. We have detected multiple hyperfine components of the $N_{K_\text{a}K_\text{c}} = 1_{01} - 0_{00}$ and $2_{02} - 1_{01}$ transitions. We derived molecular abundances with respect to ${\rm H_2}$ of (6.8$\pm$1.3)$\times 10^{-11}$ for ${\rm H_2CN}$ and of (3.1$\pm$0.7)$\times 10^{-11}$ for ${\rm H_2NC}$, and a ${\rm H_2CN}$/${\rm H_2NC}$ abundance ratio of 2.2$\pm$0.5. These detections confirm that the ${\rm H_2CN}$/${\rm H_2NC}$ ratio is $\gtrsim$2 for sources with $T_{\rm kin} > 70 \, {\rm K}$, larger than the $\sim$1 ratios previously found in colder cores ($T_{\rm kin}\sim10 \, {\rm K}$). This isomeric ratio dependence with temperature cannot be fully explained with the currently proposed gas-phase formation and destruction pathways. Grain surface reactions, including the ${\rm H_2NC} \rightarrow {\rm H_2CN}$ isomerization, deserve consideration to explain the higher isomeric ratios and ${\rm H_2CN}$ abundances observed in warm sources, where the molecules can be desorbed into the gas phase through thermal and/or shock-induced mechanisms.

6.Breakdown of the Newton-Einstein Standard Gravity at Low Acceleration in Internal Dynamics of Wide Binary Stars

Authors:Kyu-Hyun Chae

Abstract: A gravitational anomaly is found at weak gravitational acceleration $g_{\rm{N}} < 10^{-9}$ m s$^{-2}$ from analyses of the dynamics of wide binary stars selected from the Gaia EDR3 database that have accurate distances, proper motions, and reliably inferred stellar masses. Implicit high-order multiplicities are required and the multiplicity fraction is calibrated so that binary internal motions agree statistically with Newtonian dynamics at a high enough acceleration of $10^{-8}$ m s$^{-2}$. The observed sky-projected motions and separation are deprojected to the three-dimensional relative velocity $v$ and separation $r$ through a Monte Carlo method, and a statistical relation between the Newtonian acceleration $g_{\rm{N}} \equiv GM/r^2$ (where $M$ is the total mass of the binary system) and a kinematic acceleration $g \equiv v^2/r$ is compared with the corresponding relation predicted by Newtonian dynamics. The empirical acceleration relation at $< 10^{-9}$ m s$^{-2}$ systematically deviates from the Newtonian expectation. A gravitational anomaly parameter $\delta_{\rm{obs-newt}}$ between the observed acceleration at $g_{\rm{N}}$ and the Newtonian prediction is measured to be: $\delta_{\rm{obs-newt}}= 0.034\pm 0.007$ and $0.109\pm 0.013$ at $g_{\rm{N}}\approx10^{-8.91}$ and $10^{-10.15}$ m s$^{-2}$, from the main sample of 26,615 wide binaries within 200 pc. These two deviations in the same direction represent a $10\sigma$ significance. The deviation represents a direct evidence for the breakdown of standard gravity at weak acceleration. At $g_{\rm{N}}=10^{-10.15}$ m s$^{-2}$, the observed to Newton predicted acceleration ratio is $g_{\rm{obs}}/g_{\rm{pred}}=10^{\sqrt{2}\delta_{\rm{obs-newt}}}=1.43\pm 0.06$. This systematic deviation agrees with the boost factor that the AQUAL theory predicts for kinematic accelerations in circular orbits under the Galactic external field.

7.The variability of the broad-line Balmer decrement for quasars from the Sloan Digital Sky Survey Reverberation Mapping

Authors:Yan-Song Ma NJNU, Shao-Jun Li NJNU, Chen-Sheng Gu NJNU, Jian-Xia Jiang NJNU, Kai-Li Hou NJNU, Shu-Hao Qin NJNU, Wei-Hao Bian NJNU

Abstract: Based on the spectral decomposition through a code of PrepSpec, the light curves (spanning 6.5 years in the observed frame) of the broad-line Balmer decrement, i.e., the flux ratio of the broad \ha to the broad \hb line, are calculated for a sample of 44 Sloan Digital Sky Survey reverberation-mapped quasars ($z<0.53$). It is found that the logarithm of the mean broad-line Balmer decrement is 0.62 with a standard deviation of 0.15 dex. The relations between the mean Balmer decrement and the SMBH accretion properties (the luminosity, black hole mass, Eddington ratio, accretion rate) are investigated and no obvious correlations are found. It is found that there are 27 quasars ($61\%$) showing strong negative correlations between the Balmer decrement variance and the continuum variance, i.e., the Balmer decrement would be smaller with larger continuum flux. Assuming that the dust obscuration leads to the variance in the Balmer decrement and the continuum, an expected slope is $-1/3$, which is not consistent with most of measured slopes. Using the interpolated cross-correlation function, the time delays between the inverse Balmer decrement and the continuum are measured for 14 quasars with the maximum correlation coefficient larger the 0.6. It suggests that the size corresponding to the Balmer decrement lag extends from the BLR size to the torus size.

8.Efficient NIRCam Selection of Quiescent Galaxies at 3 < z < 6 in CEERS

Authors:Arianna S. Long, Jacqueline Antwi-Danso, Erini L. Lambrides, Christopher C. Lovell, Alexander de la Vega, Francesco Valentino, Jorge A. Zavala, Caitlin M. Casey, Stephen M. Wilkins, L. Y. Aaron Yung, Pablo Arrabal Haro, Micaela B. Bagley, Laura Bisigello, Katherine Chworowsky, Michael C. Cooper, Olivia R. Cooper, Asantha R. Cooray, Darren Croton, Mark Dickinson, Steven L. Finkelstein, Maximilien Franco, Katriona M. L. Gould, Michaela Hirschmann, Taylor A. Hutchison, Jeyhan S. Kartaltepe, Dale D. Kocevski, Anton M. Koekemoer, Ray A. Lucas, Jed McKinney, Casey Papovich, Pablo G. Perez-Gonzalez, Nor Pirzkal, Paola Santini

Abstract: The substantial populations of massive quiescent galaxies at $z\ge3$ challenge our understanding of rapid galaxy growth and quenching over short timescales. In order to piece together this evolutionary puzzle, more statistical samples of these objects are required. Established techniques for identifying massive quiescent galaxies are increasingly inefficient and unconstrained at $z> 3$. As a result, studies report that as much as 70\% of quiescent galaxies at $z> 3$ may be missed from existing surveys. In this work, we propose a new empirical color selection technique designed to select massive quiescent galaxies at $3\lesssim z \lesssim 6$ using JWST NIRCam imaging data. We use empirically-constrained galaxy SED templates to define a region in the $F277W-F444W$ vs. $F150W-F277W$ color plane that appears unique in capturing quiescent galaxies at $z> 3$ and minimizes contamination from other red galaxy populations. We apply this color selection criteria to the Cosmic Evolution Early Release Science (CEERS) Survey and filter out $> 99\%$ of sources. We identify 44 candidate $z\gtrsim3$ quiescent galaxies and derive volume density estimates of $n\sim1-4\times10^{-5}$ Mpc$^{-3}$ at $3< z< 5$, finding excellent agreement with existing reports on similar populations in the CEERS field. Thanks to NIRCam's wavelength coverage and sensitivity, this technique provides an efficient filter that aids in the search for these rare galaxies.

9.RIOJA I. The core of the highest redshift galaxy overdensity at $z= 7.88$ confirmed by NIRSpec/JWST

Authors:Takuya Hashimoto, Javier Álvarez-Márquez, Yoshinobu Fudamoto, Luis Colina, Akio K. Inoue, Yurina Nakazato, Daniel Ceverino, Naoki Yoshida, Luca Costantin, Yuma Sugahara, Alejandro Crespo Gómez, Carmen Blanco-Prieto, Ken Mawatari, Santiago Arribas, Rui Marques-Chaves, Miguel Pereira-Santaella, Tom J. L. C. Bakx, Masato Hagimoto, Takeshi Hashigaya, Hiroshi Matsuo, Yoichi Tamura, Mitsutaka Usui, Yi W. Ren

Abstract: The proto-clusters in the epoch of reionization, traced by galaxies overdensity regions, are ideal laboratories to study the process of stellar assembly and cosmic reionization. We present the spectroscopic confirmation of the core of the most distant proto-cluster at $z = 7.88$, A2744-z7p9OD, with the James Webb Space Telescope NIRSpec integral field unit spectroscopy. The core region includes as many as 4 galaxies detected in [O III] 4960 A and 5008 A in a small area of $\sim 3" \times 3"$, corresponding to $\sim$ 11 kpc $\times$ 11 kpc. Three member galaxies are also tentatively detected in dust continuum in ALMA Band 6, which is consistent with their red ultraviolet continuum slopes, $\beta \sim -1.3$. The member galaxies have stellar masses in the range of log($M_{*}/M_{\rm \odot}$) $\sim 7.6-9.2$ and star formation rates of $\sim 3-50$ $M_{\rm \odot}$ yr$^{-1}$, showing a diversity in their properties. FirstLight cosmological simulations reproduce the physical properties of the member galaxies including the stellar mass, [OIII] luminosity, and dust-to-stellar mass ratio, and predict that the member galaxies are on the verge of merging in a few to several tens Myr to become a large galaxy with $M_{\rm *}\sim 6\times10^{9} M_{\rm \odot}$. The presence of a multiple merger and evolved galaxies in the core region of A2744-z7p9OD indicates that environmental effects are already at work 650 Myr after the Big Bang.

10.Evolution of radioactive elements in the LMC: predictions for future gamma-ray surveys

Authors:Arianna Vasini, Francesca Matteucci, Emanuele Spitoni, Thomas Siegert

Abstract: Short-lived radionuclides, such as 26Al and 60Fe, are tracers of star formation. Therefore, their abundances can unravel the recent star formation history of the host galaxy. In view of future gamma-ray surveys, we predict the masses and fluxes of these two elements in the Large Magellanic Cloud (LMC) using new chemical evolution models. Our best model reproduces the abundance patterns of alpha/Fe ratios, the gas mass, the average metallicity, the present time supernova and nova rates observed in LMC. We show three main results: i) the best model for the LMC suggests a star formation rate very mild at the beginning with a recent burst, and a Salpeter-like initial mass function. ii) The predicted mass of 26Al is 0.33 M_Sun, 2/3 produced by massive stars and 1/3 by novae. iii) The predicted mass of 60Fe is 0.44 M_Sun, entirely produced by massive stars. This result suggests a larger fraction of 60Fe, at variance with the Milky Way. The explanation for this lies in the adopted initial mass function, that for the LMC contains more massive stars than for the Milky Way. These predictions can be useful for the COSI-SMEX mission planned for launch in 2027. The expected gamma-ray line fluxes for the 1.809 MeV line of 26Al and the 1.173 and 1.332 MeV lines of 60Fe are in the range of (0.2-2.7)x10^-6 ph cm^-2 s^-1 and (0.7-2.8)x10^-7 ph cm^-2 s^-1, respectively. This new instrument could have the sensitivity to detect the upper end of the predicted 1.8 MeV flux within its nominal two-year mission.

1.Weighing Andromeda: Mass estimates of the M~31 galaxy

Authors:Souradeep Bhattacharya

Abstract: Andromeda (M 31) is the nearest giant spiral galaxy to our Milky Way, and over the past few decades, has been dubbed the most massive member of the Local Group. I explore the evolution of the measured mass of M 31 over the past ~80 years, reviewing the different observational and modelling techniques that have developed over time to measure its mass. I discuss the best present-day constraints of the mass of M 31 and the consistency of different techniques.

2.A Catalog of Distance Determinations for the LAMOST DR8 K Giants in the Galactic Halo

Authors:Lan Zhang, Xiang-Xiang Xue, Chengqun Yang, Feilu Wang, Hans-Walter Rix, Gang Zhao, Chao Liu

Abstract: We present a catalog of distances for 19544 K giants drawn from LAMOST DR8. Most of them are located in the halo of the Milky Way up to ~120~kpc. There are 15% K giants without SDSS photometry, for which we supplements with Pan-STARRS1 (PS1) photometry calibrated to SDSS photometric system. The possible contamination of the red clumps/horizontal branch are removed according to metallicities and colors before the distance determination. Combining the LAMOST spectroscopic metallicities with the SDSS/PS1 photometry, we estimate the absolute magnitudes in SDSS $r-$band, the distance moduli, and the corresponding uncertainties through an Bayesian approach devised by Xue et al. (2014) for the SEGUE halo K-giants. The typical distance precision is about 11%. The stars in the catalog lie in a region of 4-126 kpc from the Galactic center, of which with 6, 320 stars beyond 20 kpc and 273 stars beyond 50 kpc, forming the largest spectroscopic sample of distant tracers in the Milky Way halo so far.

3.Steady states of the Parker instability: the effects of rotation

Authors:Devika Tharakkal, Anvar Shukurov, Frederick A. Gent, Graeme R. Sarson, Andrew Snodin

Abstract: We model the Parker instability in vertically stratified isothermal gas using non-ideal MHD three-dimensional simulations. Rotation, especially differential, more strongly and diversely affects the nonlinear state than the linear stage (where we confirm the most important conclusions of analytical models), and stronger than any linear analyses predict. Steady state magnetic fields are stronger and cosmic ray energy density higher than in comparable nonrotating systems. Transient gas outflows induced by the nonlinear instability persist longer, of order 2 Gyr, with rotation. Stratification combined with (differential) rotation drives helical flows, leading to mean-field dynamo. Consequently, the nonlinear state becomes oscillatory (while both the linear instability and the dynamo are non-oscillatory). The horizontal magnetic field near the midplane reverses its direction propagating to higher altitudes as the reversed field spreads buoyantly. The spatial pattern of the large-scale magnetic field may explain the alternating magnetic field directions in the halo of the edge-on galaxy NGC 4631. Our model is unique in producing a large-scale magnetic structure similar to such observation. Furthermore, our simulations show that the mean kinetic helicity of the magnetically driven flows has the sign opposite to that in the conventional non-magnetic flows. This has profound consequences for the nature of the dynamo action and large-scale magnetic field structure in the coronae of spiral galaxies which remain to be systematically explored and understood. We show that the energy density of cosmic rays and magnetic field strength are not correlated at scales of order a kiloparsec.

4.Gas, dust, and the CO-to-molecular gas conversion factor in low-metallicity starbursts

Authors:L. K. Hunt, F. Belfiore, F. Lelli, B. T. Draine, A. Marasco, S. Garcia-Burillo, G. Venturi, F. Combes, A. Weiß, C. Henkel, K. M. Menten, F. Annibali, V. Casasola, M. Cignoni, A. McLeod, M. Tosi, M. Beltran, A. Concas, G. Cresci, M. Ginolfi, N. Kumari, F. Mannucci

Abstract: The factor relating CO emission to molecular hydrogen column density, XCO, is still subject to uncertainty, in particular at low metallicity. Here, to quantify XCO at two different spatial resolutions, we exploit a dust-based method together with ALMA 12-m and ACA data and HI maps of three nearby metal-poor starbursts, NGC625, NGC1705, and NGC5253. Dust opacity at 250pc resolution is derived based on dust temperatures estimated by fitting two-temperature modified blackbodies to Herschel PACS data. By using the HI maps, we are then able to estimate dust-to-gas ratios in the atomic-gas dominated regions, and infer total gas column densities and H2 column densities as the difference with HI. Finally, from the ACA CO(1-0) maps, we derive XCO. We use a similar technique with 40 pc ALMA 12-m data for the three galaxies, but instead derive dust attenuation at 40 pc resolution from reddening maps based on VLT/MUSE data. At 250 pc resolution, XCO $\sim$ 10^22 - 10^23 cm^-2 /, 5-1000 times the Milky Way value, with much larger values than would be expected from a simple metallicity dependence. Instead at 40 pc resolution, XCO again shows large variation, but is roughly consistent with a power-law metallicity dependence, given the Z $\sim$ 1/3 Zsun metal abundances of our targets. The large scatter in both estimations could imply additional parameter dependence, that we have investigated by comparing XCO with the observed velocity-integrated brightness temperatures, ICO, as predicted by recent simulations. Indeed, larger XCO is significantly correlated with smaller ICO, but with slightly different slopes and normalizations than predicted by theory. Such behavior can be attributed to the increasing fraction of CO-faint H2 gas with lower spatial resolution. This confirms the idea the XCO is multi-variate, depending not only on metallicity but also on CO brightness temperature and beam size.

5.Mildly Relativistic Motion in the Radio Quiet Quasar PG 1351+640

Authors:Ailing Wang, Tao An, Shaoguang Guo, Luis C. Ho, Willem A. Baan, Robert Braun, Sina Chen, Xiaopeng Cheng, Philippa Hartley, Jun Yang, Yingkang Zhang

Abstract: Measuring the proper motion of the emission component in radio-quiet quasars (RQQs) could help to distinguish between the origins of the radio emission and to understand whether the jet production mechanism is the same in radio-loud quasars (RLQs) and RQQs. PG 1351+640 is one of the few RQQs suitable for proper motion studies: it has two compact components on milli-arcsecond scales, a flat-spectrum core and a steep-spectrum jet; both components are >2 mJy at 5 GHz and are well suited for Very Long Baseline Array (VLBA) observations. We compare recent VLBA observations with that made seventeen years ago and find no significant change in the core-jet separation between 2005 and 2015 (a proper motion of 0.003 mas yr-1). However, the core-jet separation increased significantly between 2015 and 2022, inferring a jet proper motion velocity of 0.063 mas yr-1, which corresponds to an apparent transverse velocity of 0.37c. The result suggests that the jet of the RQQ PG 1351+640 is mildly relativistic and oriented at a relatively small viewing angle.

6.A Census of the TW Hya Association with Gaia

Authors:K. L. Luhman

Abstract: I have used high-precision photometry and astrometry from the third data release of Gaia to perform a survey for members of the TW Hya association (TWA). I have identified candidate members that appear to share similar kinematics and ages with bona fide members compiled by Gagne et al. (2017) and I have assessed their membership using radial velocities and spectroscopic diagnostics of age from various sources. My new catalog of adopted members contains 67 Gaia sources in 55 systems. The histogram of spectral types for TWA peaks near M5 (~0.15 Msun), resembling the distributions measured for other nearby young associations. The UVW velocities of its members indicate that the association is expanding. The rate of expansion corresponds to an age of 9.6+0.9/-0.8 Myr. In a Gaia color-magnitude diagram, the members of TWA exhibit well-defined sequences of single stars and unresolved binary stars. The combined sequence of low-mass stars in TWA is indicative of an age of 11.4+1.3/-1.2 Myr when compared to the sequence for Upper Centaurus-Lupus/Lower Centaurus-Crux, for which an age of 20 Myr is assumed. Based on these expansion and isochronal ages, I have adopted an age of 10+/-2 Myr for TWA. Finally, I have used mid-infrared photometry from the Wide-field Infrared Survey Explorer to check for excess emission from circumstellar disks among the TWA members. Fourteen members have detected disks, all of which have been reported in previous studies. The fraction of members at <=M6 (>=0.1 Msun) that have full, transitional, or evolved disks is 10/52=0.19+0.08/-0.06. That value is similar to the fraction previously measured for the Upper Sco association, which is roughly coeval with TWA.

7.Clusters, Clouds, and Correlations: Relating Young Clusters to Giant Molecular Clouds in M33 and M31

Authors:Joshua Peltonen, Erik Rosolowsky, L. Clifton Johnson, Anil C. Seth, Julianne Dalcanton, Eric F. Bell, Jonathan Braine, Eric W. Koch, Margaret Lazzarini, Adam K. Leroy, Evan D. Skillman, Adam Smercina, Tobin Wainer, Benjamin F. Williams

Abstract: We use young clusters and giant molecular clouds (GMCs) in the galaxies M33 and M31 to constrain temporal and spatial scales in the star formation process. In M33, we compare the PHATTER catalogue of 1214 clusters with ages measured via colour-magnitude diagram (CMD) fitting to 444 GMCs identified from a new 35 pc resolution ALMA $^{12}$CO(2-1) survey. In M31, we compare the PHAT catalogue of 1249 clusters to 251 GMCs measured from a CARMA $^{12}$CO(1-0) survey with 20 pc resolution. Through two-point correlation analysis, we find that young clusters have a high probability of being near other young clusters, but correlation between GMCs is suppressed by the cloud identification algorithm. By comparing the positions, we find that younger clusters are closer to GMCs than older clusters. Through cross-correlation analysis of the M33 cluster data, we find that clusters are statistically associated when they are $\leq$10 Myr old. Utilizing the high precision ages of the clusters, we find that clusters older than $\approx 18$ Myr are uncorrelated with the molecular ISM. Using the spatial coincidence of the youngest clusters and GMCs in M33, we estimate that clusters spend $\approx$4-6 Myr inside their parent GMC. Through similar analysis, we find that the GMCs in M33 have a total lifetime of $\approx 11$-15 Myr. We also develop a drift model and show that the above correlations can be explained if the clusters in M33 have a 5-10 km s$^{-1}$ velocity dispersion relative to the molecular ISM.

8.The impact of HII regions on Giant Molecular Cloud properties in nearby galaxies sampled by PHANGS ALMA and MUSE

Authors:Antoine Zakardjian, Jérôme Pety, Cinthya N. Herrera, Annie Hughes, Elias Oakes, Kathryn Kreckel, Chris Faesi, Simon C. O. Glover, Brent Groves, Ralf S. Klessen, Sharon Meidt, Ashley Barnes, Francesco Belfiore, Ivana Bešlić, Frank Bigiel, Guillermo A. Blanc, Mélanie Chevance, Daniel A. Dale, Jakob den Brok, Cosima Eibensteiner, Eric Emsellem, Axel García-Rodríguez, Kathryn Grasha, Eric W. Koch, Adam K. Leroy, Daizhong Liu, Rebecca Mc Elroy, Lukas Neumann, Hsi-An Pan, Miguel Querejeta, Alessandro Razza, Erik Rosolowsky, Toshiki Saito, Francesco Santoro, Eva Schinnerer, Jiyai Sun, Antonio Usero, Elizabeth J. Watkins, Thomas Williams

Abstract: We identify giant molecular clouds (GMCs) associated with HII regions for a sample of 19 nearby galaxies using catalogs of GMCs and H regions released by the PHANGS-ALMA and PHANGS-MUSE surveys, using the overlap of the CO and H{\alpha} emission as the key criterion for physical association. We compare the distributions of GMC and HII region properties for paired and non-paired objects. We investigate correlations between GMC and HII region properties among galaxies and across different galactic environments to determine whether GMCs that are associated with HII regions have significantly distinct physical properties to the parent GMC population. We identify trends between the H{\alpha} luminosity of an HII region and the CO peak brightness and the molecular mass of GMCs that we tentatively attribute to a direct physical connection between the matched objects, and which arise independently of underlying environmental variations of GMC and HII region properties within galaxies. The study of the full sample nevertheless hides a large variability galaxy by galaxy. Our results suggests that at the ~100 pc scales accessed by the PHANGS-ALMA and PHANGS-MUSE data, pre-supernova feedback mechanisms in HII regions have a subtle but measurable impact on the properties of the surrounding molecular gas, as inferred from CO observations.

9.Ionised gas outflows over the radio AGN life cycle

Authors:Pranav Kukreti, Raffaella Morganti, Clive Tadhunter, Francesco Santoro

Abstract: Feedback from AGN is known to affect the host galaxy's evolution. In radio AGN, one manifestation of feedback is seen in gas outflows. However, it is still not well understood whether the effect of feedback evolves with the radio AGN life cycle. In this study, we investigate this link using the radio spectral shape as a proxy for the evolutionary stage of the AGN. We used [OIII] emission line spectra to trace the presence of outflows on the ionised gas. Using a sample of uniformly selected 129 radio AGN with $L_\textrm{1.4GHz}\approx10^{23}-10^{26}$ W Hz$^{-1}$, and a mean stacking analysis of the [OIII] profile, we conclude that the ionised gas outflow is linked to the radio spectral shape, and it evolves with the evolution of the radio source. We find that sources with a peak in their radio spectra (optically thick), on average, drive a broad outflow ($FWHM\approx1330\pm418$ km s$^{-1}$) with a velocity $v_\textrm{out}\approx 240$ km s$^{-1}$. However, we detect no outflow in the stacked [OIII] profile of sources without a peak in their radio spectrum. In addition, we find that individual outflow detections are kinematically more extreme in peaked than non-peaked sources. We conclude that radio jets are most effective at driving gas outflows when young, and the outflow is typically short lived. Our stacking analysis shows no significant dependence of the presence of ionised gas outflows on the radio morphology, 1.4 GHz luminosity, optical luminosity and Eddington ratio of these sources. We also identify candidate restarted AGN in our sample, whose [OIII] profiles suggest that they have more disturbed gas kinematics than their evolved counterparts, although the evidence for this is tentative. Our findings support the picture where the impact of AGN feedback changes as the source evolves, and young radio jets interact with the ambient medium, clearing a channel of gas as they expand.

1.A complete catalogue of broad-line AGNs and double-peaked emission lines from MaNGA integral-field spectroscopy of 10K galaxies: stellar population of AGNs, supermassive black holes, and dual AGNs

Authors:Youquan Fu, Michele Cappellari, Shude Mao, Shengdong Lu, Kai Zhu, Ran Li

Abstract: We analyse the integral-field spectroscopy data for the $\approx10,000$ galaxies in final data release of the MaNGA survey. We identify 188 galaxies for which the emission lines cannot be described by single Gaussian components. These galaxies can be classified into (1) 38 galaxies with broad $H\alpha$ and [OIII] $\lambda$5007 lines, (2) 101 galaxies with broad $H\alpha$ lines but no broad [OIII] $\lambda$5007 lines, and (3) 49 galaxies with double-peaked narrow emission lines. Most of the broad line galaxies are classified as Active Galactic Nuclei (AGN) from their line ratios. The catalogue helps us further understand the AGN-galaxy coevolution through the stellar population of broad-line region host galaxies and the relation between broad lines' properties and the host galaxies' dynamical properties. The stellar population properties (including mass, age and metallicity) of broad-line host galaxies suggest there is no significant difference between narrow-line Seyfert-2 galaxies and Type-1 AGN with broad $H\alpha$ lines. We use the broad-$H\alpha$ line width and luminosity to estimate masses of black hole in these galaxies, and test the $M_{BH}-\sigma_{e}$ relation in Type-1 AGN host galaxies. Furthermore we find three dual AGN candidates supported by radio images from the VLA FIRST survey. This sample may be useful for further studies on AGN activities and feedback processes.

2.Star cluster progenitors are dynamically decoupled from their parent self-gravitating molecular clouds

Authors:Nicolas Peretto, Andrew J. Rigby, Fabien Louvet, Gary A. Fuller, Alessio Traficante, Mathilde Gaudel

Abstract: The formation of stellar clusters dictates the pace at which galaxies evolve, and solving the question of their formation will undoubtedly lead to a better understanding of the Universe as a whole. While it is well known that star clusters form within parsec-scale over-densities of interstellar molecular gas called clumps, it is, however, unclear whether these clumps represent the high-density tip of a continuous gaseous flow that gradually leads towards the formation of stars, or a transition within the gas physical properties. Here, we present a unique analysis of a sample of 27 infrared dark clouds embedded within 24 individual molecular clouds that combine a large set of observations, allowing us to compute the mass and velocity dispersion profiles of each, from the scale of tens of parsecs down to the scale of tenths of a parsec. These profiles reveal that the vast majority of the clouds, if not all, are self-gravitating on all scales, and that the clumps, on parsec-scale, are often dynamically decoupled from their surrounding molecular clouds, exhibiting steeper density profiles ($\rho\propto r^{-2}$) and flat velocity dispersion profiles ($\sigma\propto r^0$), clearly departing from Larson's relations. These findings suggest that the formation of star clusters correspond to a transition regime within the properties of the self-gravitating molecular gas. We propose that this transition regime is one that corresponds to the gravitational collapse of parsec-scale clumps within stable molecular clouds.

3.Seen and unseen: bursty star formation and its implications for observations of high-redshift galaxies with JWST

Authors:Guochao Sun, Claude-André Faucher-Giguère, Christopher C. Hayward, Xuejian Shen

Abstract: Both observations and simulations have shown strong evidence for highly time-variable star formation in low-mass and/or high-redshift galaxies, which has important observational implications because high-redshift galaxy samples are rest-UV selected and therefore particularly sensitive to the recent star formation. Using a suite of cosmological "zoom-in" simulations at $z>5$ from the Feedback in Realistic Environments (FIRE) project, we examine the implications of bursty star formation histories for observations of high-redshift galaxies with JWST. We characterize how the galaxy observability depends on the star formation history. We also investigate selection effects due to bursty star formation on the physical properties measured, such as the gas fraction, specific star formation rate, and metallicity. We find the observability to be highly time-dependent for galaxies near the survey's limiting flux due to the SFR variability: as the star formation rate fluctuates, the same galaxy oscillates in and out of the observable sample. The observable fraction $f_\mathrm{obs} \sim 50\%$ at $M_{*} \sim 10^{8.5}$ to $10^{9}\,M_{\odot}$ for a JWST/NIRCam survey reaching a limiting magnitude of $m^\mathrm{lim}_\mathrm{AB} \approx 29$$-$30, representative of surveys such as JADES-Medium and CEERS. JWST-detectable galaxies near the survey limit tend to have properties characteristic of galaxies in the bursty phase: they show 10$-$30% higher cold, dense gas fractions and 80$-$100% higher specific star formation rates at a given stellar mass than galaxies below the rest-UV detection threshold. Our study represents a first step in quantifying selection effects and associated biases due to bursty star formation in studying high-redshift galaxy properties.

4.Star Formation History of the Small Magellanic Cloud: the shell substructure

Authors:Joanna D. Sakowska, Noelia E. D. Noël, Tomás Ruiz-Lara, Carme Gallart

Abstract: We present the spatially resolved star formation history (SFH) of a shell-like structure located in the northeastern Small Magellanic Cloud (SMC). We quantitatively obtain the SFH using unprecedented deep photometric data (g~24 magnitude) from the SMASH survey and colour-magnitude diagram (CMD) fitting techniques. We consider, for the first time, the SMC's line-of-sight depth and its optical effects on the CMDs. The SFH presents higher accuracy when a line-of-sight depth of ~3 Kpc is simulated. We find young star formation enhancements at ~150 Myr, ~200 Myr, ~450 Myr, ~650 Myr, and ~1 Gyr. Comparing the shell's SFH with the Large Magellanic Cloud's (LMC) northern arm SFH we show strong evidence of synchronicity from at least the past ~2.8 Gyr and, possibly, the past ~3.5 Gyr. Our results place constraints on the orbital history of the Magellanic Clouds which, potentially, have implications on their dynamical mass estimates.

5.The Andromeda Galaxy's Last Major Merger: Constraints from the survey of Planetary Nebulae

Authors:Souradeep Bhattacharya, Magda Arnaboldi, Ortwin Gerhard, Nelson Caldwell, Chiaki Kobayashi, Francois Hammer, Yanbin Yang, Kenneth C. Freeman, Johanna Hartke, Alan McConnachie

Abstract: The Andromeda galaxy (M 31) has experienced a tumultuous merger history as evidenced by the many substructures present in its inner halo. We use planetary nebulae (PNe) as chemodynamic tracers to shed light on the recent merger history of M 31. We identify the older dynamically hotter thicker disc in M 31 and a distinct younger dynamically colder thin disc. The two discs are also chemically distinct with the PN chemodynamics implying their formation in a `wet' major merger (mass ratio ~1:5) ~2.5-4.5 Gyr ago. From comparison of PN line-of-sight velocities in the inner halo substructures with predictions of a major-merger model in M 31, we find that the same merger event that formed the M 31 thick and thin disc is also responsible for forming these substructures. We thereby obtain constraints on the recent formation history of M 31 and the properties of its cannibalized satellite.

6.Tracing Pop III supernovae with extreme energies through the Sculptor dwarf spheroidal galaxy

Authors:Ása Skúladóttir, Irene Vanni, Stefania Salvadori, Romain Lucchesi

Abstract: The Sculptor dwarf spheroidal galaxy is old and metal-poor, making it ideal to study the earliest chemical enrichment in the Local Group. We followed up the most metal-poor star known in this (or any external) galaxy, AS0039, with high-resolution ESO VLT/UVES spectra. Our new analysis confirmed its low metallicity, [Fe/H]=-3.90, and that it is extremely C-poor, with A(C)=+3.60, which corresponds to [C/Fe]=-0.33 (accounting for internal mixing). This adds to the evidence of Sculptor being intrinsically C-poor at low [Fe/H]. However, here we also report a new discovery of a carbon-enhanced metal-poor star in Sculptor, DR20080, with no enhancement of Ba (CEMP-no), indicative of enrichment by zero-metallicity low-energy supernovae. This is the first evidence of a dual population of CEMP-no and C-normal stars in Sculptor at $\rm[Fe/H]\leq{-3}$. The fraction of CEMP-no stars is still low, $9^{+11}_{-8}\%$ at $\rm -4\leq[Fe/H]\leq-3$, compared to the significantly higher fraction in the Milky Way halo, $\approx40\%$. In addition, we re-derive chemical abundances of light, $\alpha$-, iron peak, and neutron-capture elements in all Sculptor stars at $\rm [Fe/H]\leq-2.8$, with available high-resolution spectra. Our results show that at these low [Fe/H], Sculptor is deficient in light elements (e.g. C, Na, Al, Mg) relative to both the Milky Way halo, and ultra-faint dwarf galaxies, pointing towards significant contribution of high-energy supernovae. Furthermore, the abundance pattern of the star AS0039 is best fitted with a zero-metallicity hypernova progenitor, with a mass of $M=20$M$_\odot$. Our results in Sculptor, at $\rm[Fe/H]\leq-3$, therefore suggest significant enrichment by both very low-energy supernovae and hypernovae, solidifying this galaxy as one of the benchmarks for understanding the energy distribution of the first supernova in the Universe.

7.Dynamical hotness, star formation quenching and growth of supermassive black holes

Authors:Hui Hong, Huiyuan Wang, H. J. Mo, Ziwen Zhang, Guangwen Chen, Wentao Luo, Tinggui Wang, Pengfei Li, Renjie Li, Yao yao, Aoxiang Jiang

Abstract: A stellar system is dynamically hot when its kinetic energy is dominated by random motion represented by the velocity dispersion $\sigma_{\rm hot} (M_*)$. We use MaNGA data to obtain inner and outer dispersion of a galaxy, $\sigma_{\rm in}$ and $\sigma_{\rm out}$, to characterize its dynamical status and study its connection with star formation quenching and the growth of supermassive black hole (SMBH). We divide galaxies into fully quenched (FQGs), partially quenched (PQGs) and fully star-forming (FSGs) populations, and identify quenched central cores (QCCs) in PQGs. The galaxy distribution in $\sigma_{\rm in}/\sigma_{\rm hot}$-$\sigma_{\rm out}/\sigma_{\rm hot}$ diagram is L-shaped, consisting of a horizontal sequence ($\sigma_{\rm out}/\sigma_{\rm hot}\sim0$) and a vertical sequence ($\sigma_{\rm in}/\sigma_{\rm hot}\sim1$). FQGs and QCCs are located at the top of vertical sequence, $\sigma_{\rm out}/\sigma_{\rm hot}\sim1$, therefore they are dynamically hot over their entire bodies. PQGs reside along vertical sequence, so they have hot center but cold outskirt. FSGs are diverse and can be found in both sequences. Galaxy structural properties, star formation and AGN activities make a transition along horizontal sequence at $\log(\sigma_{\rm in}/\sigma_{\rm hot})\sim-0.3$, and along vertical sequence at $\log(\sigma_{\rm out}/\sigma_{\rm hot})\sim-0.3$. The fractions of optical AGNs and barred galaxies increase rapidly in the first transition and decline rapidly in the second; radio galaxies are located at the top of vertical sequence. Our results demonstrate that star formation quenching and SMBH growth are effective only in dynamically hot systems. A simple model along this line can reproduce the observed SMBH scaling relations. We discuss how secular processes and strong interactions can make a system dynamically hot, and lead to the SMBH growth and star formation quenching.

8.Evidence for Large Scale, Rapid Gas Inflows in z~2 Star Forming Disks

Authors:R. Genzel, J. -B. Jolly, D. Liu, S. H. Price, N. M. Förster Schreiber, L. J. Tacconi, R. Herrera-Camus, C. Barfety, A. Burkert, Y. Cao, R. I. Davies, A. Dekel, M. M. Lee, L. L. Lee, D. Lutz, T. Naab, R. Neri, A. Nestor Shachar, S. Pastras, C. Pulsoni, A. Renzini, K. Schuster, T. T. Shimizu, F. Stanley, A. Sternberg, H. Übler

Abstract: We report high quality H${\alpha}$/CO, imaging spectroscopy of nine massive, disk galaxies on the star forming, Main Sequence (henceforth 'SFGs'), near the peak of cosmic galaxy evolution (z~1.1-2.5), taken with the ESO-VLT, IRAM-NOEMA and ALMA. We fit the major axis position-velocity cuts with beam-convolved, forward models with a bulge, a turbulent rotating disk, and a dark matter (DM) halo. We include priors for stellar and molecular gas masses, optical light effective radii and inclinations, and DM masses from our previous rotation curve analyses of these galaxies. We then subtract the inferred 2D model-galaxy velocity and velocity dispersion maps from those of the observed galaxies. We investigate whether the residual velocity and velocity dispersion maps show indications for radial flows. We also carry out kinemetry, a model-independent tool for detecting radial flows. We find that all nine galaxies exhibit significant non-tangential flows. In six SFG, the inflow velocities ($v_r$~30-90 km s$^{-1}$, 10-30% of the rotational component) are along the minor axis of these galaxies. In two cases the inflow appears to be off the minor axis. The magnitudes of the radial motions are in broad agreement with the expectations from analytic models of gravitationally unstable, gas rich disks. Gravitational torques due to clump and bar formation, or spiral arms, drive gas rapidly inward and result in the formation of central disks and large bulges. If this interpretation is correct, our observations imply that gas is transported into the central regions on ~10 dynamical time scales.

9.M92 (NGC~6341) Is a Metal-Complex Globular Cluster with an Atypical Primordial Population

Authors:Jae-Woo Lee

Abstract: We present a multiple stellar population study of the metal-poor globular cluster (GC) M92 (NGC 6341), which is long known for the substantial metallicity dispersion, using our own photometric system. We find two groups with slightly different mean metallicities, the metal-poor (MP) stars with [Fe/H] = $-$2.412$\pm$0.03, while the metal-rich (MR) ones with $-$2.282$\pm$0.002. The MP constitutes about 23\% of the total mass with a more central concentration. Our populational tagging based on the [C/Fe] and [N/Fe] provides the mean n(P):n(I):n(E) = 32.2:31.6:36.2 ($\pm$2.4), where P, I, and E denote the primordial, intermediate, and extreme populations, respectively. Our populational number ratio is consistent with those of others. However, the MP has a significantly different populational number ratio than the mean value, and the domination of the primordial population in the MP is consistent with observations of Galactic GCs that less massive GCs contain larger fractions of the primordial population. Structural and constituent differences between the MP and MR may indicate that M92 is a merger remnant in a dwarf galaxy environment, consistent with recent suggestions that M92 is a GC in a dwarf galaxy or a remnant nucleus of the progenitor galaxy. Discrepancy between our method and those widely used for the HST photometry exists in the primordial population. Significant magnesium and oxygen depletions of $-$0.8 and $-$0.3 dex, respectively, and helium enhancement of $\Delta Y$ $\gtrsim$ 0.03 are required to explain the presence of this abnormal primordial group. No clear explanation is available with limited information of detailed elemental abundances.

10.JWST NIRSpec spectroscopy of the triply-lensed $z = 10.17$ galaxy MACS0647$-$JD

Authors:Tiger Yu-Yang Hsiao, Abdurro'uf, Dan Coe, Rebecca L. Larson, Intae Jung, Matilde Mingozzi, Pratika Dayal, Nimisha Kumari, Vasily Kokorev, Anton Vikaeus, Gabriel Brammer, Lukas J. Furtak, Angela Adamo, Felipe Andrade-Santos, Jacqueline Antwi-Danso, Marusa Bradac, Larry D. Bradley, Tom Broadhurst, Adam C. Carnall, Christopher J. Conselice, Jose M. Diego, Megan Donahue, Jan J. Eldridge, Seiji Fujimoto, Alaina Henry, Svea Hernandez, Taylor A. Hutchison, Bethan L. James, Colin Norman, Hyunbae Park, Norbert Pirzkal, Marc Postman, Massimo Ricotti, Jane R. Rigby, Eros Vanzella, Brian Welch, Stephen M. Wilkins, Rogier A. Windhorst, Xinfeng Xu, Erik Zackrisson, Adi Zitrin

Abstract: We present JWST/NIRSpec prism spectroscopy of MACS0647-JD, the triply-lensed $z \sim 11$ candidate discovered in HST imaging and spatially resolved by JWST imaging into two components A and B. Spectroscopy of component A yields a spectroscopic redshift $z=10.17$ based on 7 detected emission lines: CIII] $\lambda\lambda$1907,1909, [OII] $\lambda$3727, [NeIII] $\lambda$3869, [NeIII] $\lambda$3968, H$\delta$ $\lambda$4101, H$\gamma$ $\lambda$4340, and [OIII] $\lambda$4363. These are the second-most distant detections of these emission lines to date, in a galaxy observed just 460 million years after the Big Bang. Based on observed and extrapolated line flux ratios we derive a gas-phase metallicity $Z =$ log(O/H) = $7.5 - 8.0$, or $(0.06 - 0.2)$ $Z_\odot$, ionization parameter log($U$) $\sim -1.9\pm0.2$, and an ionizing photon production efficiency ${\rm log}(\xi_{\rm ion})=25.2\pm0.2\,$erg$^{-1}$ Hz. The spectrum has a softened Lyman-$\alpha$ break, evidence for a strong Ly$\alpha$ damping wing, suggesting that MACS0647-JD was unable to ionize its surroundings beyond its immediate vicinity ($R_{\text{HII}} \ll 1$ pMpc). The Ly$\alpha$ damping wing also suppresses the F150W photometry, explaining the slightly overestimated photometric redshift $z = 10.6 \pm 0.3$. MACS0647-JD has a stellar mass log($M/M_\odot$) = $8.1 \pm 0.3$, including $\sim$ 6$\times 10^7 M_\odot$ in component A, most of which formed recently (within $\sim$ 20 Myr) with a star formation rate $2\pm1 M_\odot$ / yr, all within an effective radius $70\pm24\,$pc. The smaller component B ($r \sim 20$) pc is likely older ($\sim$100 Myr) with more dust ($A_V \sim 0.1$ mag), as found previously. Spectroscopy of a fainter companion galaxy C separated by a distance of \about\ 3$\,$kpc reveals a Lyman break consistent with $z = 10.17$. MACS0647-JD is likely the most distant galaxy merger known.

1.The origin of dust polarization in the Orion Bar

Authors:Valentin J. M. Le Gouellec, B-G Andersson, Archana Soam, Thiébaut Schirmer, Joseph M. Michail, Enrique Lopez-Rodriguez, Sophia Flores, David T. Chuss, John E. Vaillancourt, Thiem Hoang, Alex Lazarian

Abstract: The linear polarization of thermal dust emission provides a powerful tool to probe interstellar and circumstellar magnetic fields, because aspherical grains tend to align themselves with magnetic field lines. While the Radiative Alignment Torque (RAT) mechanism provides a theoretical framework to this phenomenon, some aspects of this alignment mechanism still need to be quantitatively tested. One such aspect is the possibility that the reference alignment direction changes from the magnetic field ("B-RAT") to the radiation field k-vector ("k-RAT") in areas of strong radiation fields. We investigate this transition toward the Orion Bar PDR, using multi-wavelength SOFIA HAWC+ dust polarization observations. The polarization angle maps show that the radiation field direction is on average not the preferred grain alignment axis. We constrain the grain sizes for which the transition from B-RAT to k-RAT occur in the Orion Bar (grains > 0.1 {\mu}m toward the most irradiated locations), and explore the radiatively driven rotational disruption that may take place in the high-radiation environment of the Bar for large grains. While the grains susceptible to rotational disruption should be in supra-thermal rotation and aligned with the magnetic field, k-RAT aligned grains would rotate at thermal velocities. We find that the grain size at which the alignment shifts from B-RAT to k-RAT corresponds to grains too large to survive the rotational disruption. Therefore, we expect a large fraction of grains to be aligned at supra-thermal rotation with the magnetic field, and potentially be subject to rotational disruption depending on their tensile strength.

2.The PAU Survey: Close galaxy pairs identification and analysis

Authors:E. J. Gonzalez, F. Rodriguez, D. Navarro-Gironés, E. Gaztañaga, M. Siudek, D. García Lambas, A. L. O'Mill, P. RenardL. Cabayol, J. Carretero, R. Casas, J. De Vicente, M. Eriksen, E. Fernandez, J. Garcia-Bellido, H. Hildebrandt, R. Miquel, C. Padilla, E. Sanchez, I. Sevilla-Noarbe, P. Tallada-Crespí, A. Wittje

Abstract: Galaxy pairs constitute the initial building blocks of galaxy evolution, which is driven through merger events and interactions. Thus, the analysis of these systems can be valuable in understanding galaxy evolution and studying structure formation. In this work, we present a new publicly available catalogue of close galaxy pairs identified using photometric redshifts provided by the Physics of the Accelerating Universe Survey (PAUS). To efficiently detect them we take advantage of the high-precision photo$-z$ ($\sigma_{68} < 0.02$) and apply an identification algorithm previously tested using simulated data. This algorithm considers the projected distance between the galaxies ($r_p < 50$ kpc), the projected velocity difference ($\Delta V < 3500$ km/s) and an isolation criterion to obtain the pair sample. We applied this technique to the total sample of galaxies provided by PAUS and to a subset with high-quality redshift estimates. Finally, the most relevant result we achieved was determining the mean mass for several subsets of galaxy pairs selected according to their total luminosity, colour and redshift, using galaxy-galaxy lensing estimates. For pairs selected from the total sample of PAUS with a mean $r-$band luminosity $10^{10.6} h^{-2} L_\odot$, we obtain a mean mass of $M_{200} = 10^{12.2} h^{-1} M_\odot$, compatible with the mass-luminosity ratio derived for elliptical galaxies. We also study the mass-to-light ratio $M/L$ as a function of the luminosity $L$ and find a lower $M/L$ (or steeper slope with $L$) for pairs than the one extrapolated from the measurements in groups and galaxy clusters.

3.Detections of 21-cm absorption with a blind FAST survey at z $\leqslant$ 0.09

Authors:Wenkai Hu, Yougang Wang, Yichao Li, Yidong Xu, Wenxiu Yang, Guilaine Lagache, Ue-Li Pen, Zheng Zheng, Shuanghao Shu, Yinghui Zheng, Di Li, Tao-Chung Ching, Xuelei Chen

Abstract: We present the early science results from a blind search of the extragalactic HI 21-cm absorption lines at z $\leqslant$ 0.09 with the drift-scan observation of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We carried out the search using the data collected in 643.8 hours by the ongoing Commensal Radio Astronomy FasT Survey (CRAFTS), which spans a sky area of 3155 deg$^{2}$ and covers 44827 radio sources with a flux density greater than 12 mJy. Due to the radio frequency interference (RFI), only the relatively clean data in the frequency range of 1.3-1.45 GHz are used in the present work. Under the assumption of $T_{s}/c_{f}$ = 100 K, the total completeness-corrected comoving absorption path length spanned by our data and sensitive to Damped Lyman $\alpha$ Absorbers (DLAs) are $\Delta X^{inv}$ = 8.33$\times10^3$ ($\Delta z^{inv} = 7.81\times10^{3}$) for intervening absorption. For associated absorption, the corresponding values are $\Delta X^{asc}$ = 12.8 ($\Delta z^{asc} = 11.9$). Three known HI absorbers (UGC 00613, 3C 293 and 4C +27.14) and two new HI absorbers (towards NVSS J231240-052547 and NVSS J053118+315412) are detected blindly. We fit the HI profiles with multi-components Gaussian functions and calculate the redshift (0.063, 0.066), width, flux density, optical depth and HI column densities for each absorption. Our results demonstrate the power of FAST in blindly searching HI absorbers. For absorption towards NVSS J231240-052547, the optical counterparts are faint and currently lack existing spectra. The most likely interpretation is that a radio-loud active galactic nucleus (AGN) is faint in the optical as the background source, with a faint optical absorber in between. NVSS J053118+315412 exhibits an associated absorption with a complex profile, which may suggest unsettled gas structures or gas accretion onto the supermassive black hole (SMBH).

4.Tailoring galaxies: size-luminosity-surface brightness relations of bulges and disks along the morphological sequence

Authors:Louis Quilley, Valérie de Lapparent

Abstract: We measure the scaling relations of the bulges and disks of the EFIGI galaxies in the nearby Universe versus morphology, using bulge and disk decomposition of SDSS gri images with SourceXtractor++. The Kormendy (1977) relation between effective surface brightness and effective radius of E galaxies extends to the bulges of types S0 to Sb, whereas fainter and smaller bulges of later Hubble types depart from it, with decreasing bulge-to-total ratio (B/T) and S\'ersic indices. There is a continuous transition from pseudo-bulges to classical ones, proposed to occur for g magnitudes between -17.8 to -19.1. The size-luminosity relations for E and dE types are steeper and similar to those from Binggeli et al. (1984), resp., below which EFIGI lenticular and spiral bulges display a curved relation. The disks and irregulars also follow a continuous curved size-luminosity relation such that while they grow, they first brighten and then stabilize in surface brightness. Moreover, we obtain the unprecedented result that the effective radii of both the bulges and disks of spirals increase as power-laws of B/T, with a steeper increase for the bulges. The increase with B/T is much steeper and similar for the bulges and disks of lenticulars. The ratio of disk-to-bulge effective radii varies accordingly across 2 orders of magnitude in B/T for all lenticular and spiral types, with a mean disk-to-bulge ratio decreasing from ~15 for Sbc to Scd types to ~6 for S0. We tabulate all derived scaling relations, so that they can be used to build realistic mock images of nearby galaxies. The new curved size-luminosity relations will prevent over or under estimates of bulge, disk and galaxy sizes at all magnitudes. These results complement the analysis of Quilley & de Lapparent (2022) by providing the joint size and luminosity variations of bulges and disks, as they evolve reversely along the Hubble sequence.

5.EMPRESS. XIII. Chemical Enrichments of Young Galaxies Near and Far at z ~ 0 and 4-10: Fe/O, Ar/O, S/O, and N/O Measurements with Chemical Evolution Model Comparisons

Authors:Kuria Watanabe, Masami Ouchi, Kimihiko Nakajima, Yuki Isobe, Nozomu Tominaga, Akihiro Suzuki, Miho N. Ishigaki, Ken'ichi Nomoto, Koh Takahashi, Yuichi Harikane, Shun Hatano, Haruka Kusakabe, Takashi J. Moriya, Moka Nishigaki, Yoshiaki Ono, Masato Onodera, Yuma Sugahara

Abstract: We present gas-phase elemental abundance ratios of 7 local extremely metal-poor galaxies (EMPGs) including our new Keck/LRIS spectroscopy determinations together with 33 JWST $z\sim 4-10$ star-forming galaxies in the literature, and compare chemical evolution models. We develop chemical evolution models with the yields of core-collapse supernovae (CCSNe), Type Ia supernovae, hypernovae (HNe), and pair-instability supernovae (PISNe), and compare the EMPGs and high-$z$ galaxies in conjunction with dust depletion contributions. We find that high Fe/O values of EMPGs can (cannot) be explained by PISN metal enrichments (CCSN/HN enrichments even with the mixing-and-fallback mechanism enhancing iron abundance), while that the observed Ar/O and S/O values are much smaller than the predictions of the PISN models. The abundance ratios of the EMPGs can be explained by the combination of Type Ia SNe and CCSNe/HNe whose inner layers of argon and sulfur mostly fallback, which are comparable with Sculptor stellar chemical abundance distribution, suggesting that early chemical enrichment is taken place in the EMPGs. Comparing our chemical evolution models with the star-forming galaxies at $z\sim 4-10$, we find that the Ar/O and S/O ratios of the high-$z$ galaxies are comparable with those of the CCSNe/HNe models, while majority of the high-$z$ galaxies do not have constraints good enough to rule out contributions from PISNe. The high N/O ratio recently reported in GN-z11 cannot be explained even by rotating PISNe, but could be reproduced by the winds of rotating Wolf Rayet stars that end up as a direct collapse.

6.EMPRESS. XIV. Strong High Ionization Lines of Young Galaxies at $z=0-8$: Ionizing Spectra Consistent with the Intermediate Mass Black Holes with $M_{\rm BH}\sim 10^3-10^6\ M_\odot$

Authors:Shun Hatano, Masami Ouchi, Hiroya Umeda, Kimihiko Nakajima, Toshihiro Kawaguchi, Yuki Isobe, Shohei Aoyama, Kuria Watanabe, Yuichi Harikane, Haruka Kusakabe, Akinori Matsumoto, Takashi J. Moriya, Moka Nishigaki, Yoshiaki Ono, Masato Onodera, Yuma Sugahara, Akihiro Suzuki, Yi Xu, Yechi Zhang

Abstract: We present ionizing spectra estimated at 13.6--100 eV for ten dwarf galaxies with strong high ionization lines of He {\sc {ii}}$\lambda$4686 and [Ne {\sc{v}}]$\lambda$3426 ([Ne {\sc{iv}}]$\lambda$2424) at $z=0$ ($z=8$) that are identified in our Keck/LRIS spectroscopy and the literature (the JWST ERO program). With the flux ratios of these high ionization lines and $>10$ low-ionization lines of hydrogen, helium, oxygen, neon, and sulfur, we determine ionizing spectra consisting of stellar and non-thermal power-law radiation by photoionization modeling with free parameters of nebular properties including metallicity and ionization parameter, cancelling out abundance ratio differences. We find that all of the observed flux ratios are well reproduced by the photoinization models with the power law index $\alpha_{\rm EUV}$ of $\alpha_{\rm EUV}\sim (-1)-0$ and the luminosity $L_{\rm EUV}$ of $L_{\rm EUV}\sim 10^{40}-10^{42}$ erg s$^{-1}$ at $\sim 55-100$ eV for six galaxies, while four galaxies include large systematics in $\alpha_{\rm EUV}$ caused by stellar radiation contamination. We then compare $\alpha_{\rm EUV}$ and $L_{\rm EUV}$ of these six galaxies with those predicted by the black hole (BH) accretion disk models, and find that these galaxies have moderately soft/luminous ionizing spectra whose $\alpha_{\rm EUV}$ and $L_{\rm EUV}$ are similar to those of the intermediate mass black holes (IMBHs) in BH accretion disk models. Confirming these results with a known IMBH having a mass $M_{\rm BH}$ of $M_{\rm BH}=10^{5.75} \ M_\odot$, we find that four local galaxies and one $z=7.665$ galaxy have ionizing spectra consistent with those of IMBHs with $M_{\rm BH} \sim 10^3-10^5 \ M_\odot$.

7.An Interferometric SETI Observation of Kepler-111 b

Authors:Kelvin Wandia

Abstract: The application of Very Long Baseline Interferometry (VLBI) to the Search for Extraterrestrial Intelligence (SETI) has been limited to date, despite the technique offering many advantages over traditional single-dish SETI observations. In order to further develop interferometry for SETI, we used the European VLBI Network (EVN) at $21$~cm to observe potential secondary phase calibrators in the Kepler field. Unfortunately, no secondary calibrators were detected. However, a VLBA primary calibrator in the field, J1926+4441, offset only $\sim1.88'$ from a nearby exoplanet Kepler-111~b, was correlated with high temporal $\left(0.25 \ \rm{s}\right)$ and spectral $\left(16384 \times 488\ \rm{Hz \ channels}\right)$ resolution. During the analysis of the high-resolution data, we identified a spectral feature that was present in both the auto and cross-correlation data with a central frequency of $1420.424\pm0.0002$ MHz and a width of 0.25 MHz. We demonstrate that the feature in the cross-correlations is an artefact in the data, associated with a significant increase in each telescope's noise figure due to the presence of \ion{H}{i} in the beam. This would typically go unnoticed in data correlated with standard spectral resolution. We flag (excluded from the subsequent analysis) these channels and phase rotate the data to the location of Kepler-111~b aided by the GAIA catalogue and search for signals with $\rm{SNR}>7$. At the time of our observations, we detect no transmitters with an Equivalent Isotropically Radiated Power (EIRP) > $\sim4\times10^{15}$ W.

8.Binary Formation in a 100 $μ$m-dark Massive Core

Authors:Shuo Kong, Héctor G. Arce, John J. Tobin, Yichen Zhang, María José Maureira, Kaitlin M. Kratter, Thushara G. S. Pillai

Abstract: We report high-resolution ALMA observations toward a massive protostellar core C1-Sa ($\sim$30 M$_\odot$) in the Dragon Infrared Dark Cloud. At the resolution of 140 AU, the core fragments into two kernels (C1-Sa1 and C1-Sa2) with a projected separation of $\sim$1400 AU along the elongation of C1-Sa, consistent with a Jeans length scale of $\sim$1100 AU. Radiative transfer modeling using RADEX indicates that the protostellar kernel C1-Sa1 has a temperature of $\sim$75 K and a mass of 0.55 M$_\odot$. C1-Sa1 also likely drives two bipolar outflows, one being parallel to the plane-of-the-sky. C1-Sa2 is not detected in line emission and does not show any outflow activity but exhibits ortho-H$_2$D$^+$ and N$_2$D$^+$ emission in its vicinity, thus it is likely still starless. Assuming a 20 K temperature, C1-Sa2 has a mass of 1.6 M$_\odot$. At a higher resolution of 96 AU, C1-Sa1 begins to show an irregular shape at the periphery, but no clear sign of multiple objects or disks. We suspect that C1-Sa1 hosts a tight binary with inclined disks and outflows. Currently, one member of the binary is actively accreting while the accretion in the other is significantly reduced. C1-Sa2 shows hints of fragmentation into two sub-kernels with similar masses, which requires further confirmation with higher sensitivity.

1.An Enigmatic 380 kpc Long Linear Collimated Galactic Tail

Authors:Dennis Zaritsky, Jacob P. Crossett, Yara L. Jaffé, Richard Donnerstein, Ananthan Karunakaran, Donghyeon J. Khim, Ana C. C. Lourenço, Kristine Spekkens, Ming Sun, Benedetta Vulcani

Abstract: We present an intriguing, serendipitously-detected system consisting of an S0/a galaxy, which we refer to as the "Kite", and a highly-collimated tail of gas and stars that extends over 380 kpc and contains pockets of star formation. In its length, narrowness, and linearity the Kite's tail is an extreme example relative to known tails. The Kite (PGC 1000273) has a companion galaxy, Mrk 0926 (PGC 070409), which together comprise a binary galaxy system in which both galaxies host active galactic nuclei. Despite this systems being previously searched for signs of tidal interactions, the tail had not been discovered prior to our identification as part of the validation process of the SMUDGes survey for low surface brightness galaxies. We confirm the kinematic association between various H$\alpha$ knots along the tail, a small galaxy, and the Kite galaxy using optical spectroscopy obtained with the Magellan telescope and measure a velocity gradient along the tail. The Kite shares characteristics common to those formed via ram pressure stripping ("jellyfish" galaxies) and formed via tidal interactions. However, both scenarios face significant challenges that we discuss, leaving open the question of how such an extreme tail formed. We propose that the tail resulted from a three-body interaction from which the lowest-mass galaxy was ejected at high velocity.

2.Ly$α$ at Cosmic Dawn with a Simulated Roman Grism Deep Field

Authors:Isak G. B. Wold, Sangeeta Malhotra, James E. Rhoads, Vithal Tilvi, Austen Gabrielpillai

Abstract: The slitless grism on the Nancy Grace Roman Space Telescope will enable deep near-infrared spectroscopy over a wide field of view. We demonstrate Roman's capability to detect Ly$\alpha$ galaxies at $z>7$ using a multi-position-angle (PA) observational strategy. We simulate Roman grism data using a realistic foreground scene from the COSMOS field. We also input fake Ly$\alpha$ galaxies spanning redshift z=7.5-10.5 and a line-flux range of interest. We show how a novel data cube search technique -- CUBGRISM -- originally developed for GALEX can be applied to Roman grism data to produce a Ly$\alpha$ flux-limited sample without the need for continuum detections. We investigate the impact of altering the number of independent PAs and exposure time. A deep Roman grism survey with 25 PAs and a total exposure time of $70$hrs can achieve Ly$\alpha$ line depths comparable to the deepest $z=7$ narrow-band surveys ($L_{{\rm{Ly}}\alpha}\gtrsim10^{43}$erg s$^{-1}$). Assuming a null result, where the opacity of the intergalactic medium (IGM) remains unchanged from $z\sim7$, this level of sensitivity will detect $\sim400$ deg$^{-2}$ Ly$\alpha$ emitters from $z=7.25-8.75$. A decline from this expected number density is the signature of an increasing neutral hydrogen fraction and the onset of reionization. Our simulations indicate that a deep Roman grism survey has the ability to measure the timing and magnitude of this decline, allowing us to infer the ionization state of the IGM and helping us to distinguish between models of reionization.

3.Generalizations of Quasilinear MOND (QUMOND)

Authors:Mordehai Milgrom

Abstract: I present a class of theories that generalize quasilinear MOND (QUMOND). Like QUMOND, these GQUMOND theories require solving only the linear Poisson equation (twice). Unlike QUMOND, their Lagrangian depends on higher derivatives of the Newtonian potential. They thus dictate different ``phantom'' densities as virtual sources in the Poisson equation for the MOND potential. These theories might open new avenues to more fundamental theories, and have much heuristic value. I use them to demonstrate that even within limited classes of modified-gravity formulations of MOND, theories can differ substantially on lower-tier MOND predictions. Such GQUMOND theories force, generically, the introduction of dimensioned constants other than the MOND acceleration, $a_0$, such as a length, a frequency, etc. As a result, some of these theories reduce to QUMOND itself only, e.g., on length scales (or, in other versions, dynamical times) larger than some critical value. But in smaller systems (or, alternatively, in ones with shorter dynamical times), MOND effects are screened, even if their internal accelerations are smaller than $a_0$. In such theories it is possible that MOND (expressed as QUMOND) applies on galactic scales, but its departures from Newtonian dynamics are substantially suppressed in some subgalactic systems -- such as binary stars, and open, or globular star clusters. The same holds for the effect of the galactic field on dynamics in the inner solar system, which can be greatly suppressed compared with what QUMOND predicts. Tidal effects of a galaxy on smaller subsystems are the same as in QUMOND, for the examples I consider. I also describe briefly versions that do not involve dimensioned constants other than $a_0$, and yet differ from QUMOND in important ways.

1.Joint Modelling of Dust Scattering and Thermal Emission: The Spider Complex

Authors:Jielai Zhang, Peter G Martin, Ryan Cloutier, Natalie Price-Jones, Roberto Abraham, Pieter van Dokkum, Allison Merritt

Abstract: Observations across the electromagnetic spectrum of radiative processes involving interstellar dust -- emission, extinction, and scattering -- are used to constrain the parameters of dust models and more directly to aid in foreground removal of dust for extragalactic and cosmology observations. The more complementary observations, the better. Here, we quantify the relationship between scattered light and thermal emission from dust in a diffuse (cirrus) intermediate latitude cloud, Spider, using data from the Dragonfly Telephoto Array and the Herschel Space Observatory. A challenge for optical observations of faint cirrus is accurate removal of a contaminating spatially varying sky background. We present a technique to analyse two images of the same cirrus field concurrently, correlating pixel values to capture the relationship and simultaneously fitting the sky background as a complex non-correlating additive component. For the Spider, we measure a $g-r$ color of 0.644$\pm 0.024$ and a visible wavelength to 250 $\mu$m intensity ratio of $10^{-3} \times (0.855 \pm0.025)$ and $10^{-3} \times (1.55\pm0.08)$ for $g$ and $r$-band respectively. We show how to use any dust model that matches the thermal dust emission to predict an upper limit to the amount of scattered light. The actual brightness of the cirrus will be fainter than this limit because of anisotropic scattering by the dust combined with anisotropy of the incident interstellar radiation field (ISRF). Using models of dust and the ISRF in the literature we illustrate that the predicted brightness is indeed lower, though not as faint as the observations indicate.

2.Local Group Galaxies from an External Perspective

Authors:Stacy McGaugh

Abstract: I discuss Local Group galaxies from the perspective of external galaxies that define benchmark scaling relations. Making use of this information leads to a model for the Milky Way that includes bumps and wiggles due to spiral arms. This model reconciles the terminal velocities observed in the interstellar medium with the rotation curve derived from stars, correctly predicts the gradual decline of the outer rotation curve ($dV/dR = -1.7\;\mathrm{km}\,\mathrm{s}^{-1}\,\mathrm{kpc}^{-1}$), and extrapolates well out to 50 kpc. Rotationally supported Local Group galaxies are in excellent agreement with the baryonic Tully-Fisher relation. Pressure supported dwarfs that are the most likely to be in dynamical equilibrium also align with this relation. Local Group galaxies thus appear to be normal members of the low redshift galaxy population. There is, however, a serious tension between the dynamical masses of the Milky Way and M31 ($M_{200} \approx 1.4$ and $1.6 \times 10^{12}\;\mathrm{M}_{\odot}$, respectively) and those expected from the stellar mass-halo mass relation of abundance matching ($M_{200} \approx 3$ and $20 \times 10^{12}\;\mathrm{M}_{\odot}$, respectively).

1.MeerKAT view of the Dancing Ghosts -- Peculiar Galaxy Pair PKS 2130-538 in Abell 3785

Authors:Velibor Velović, William D. Cotton, Miroslav D. Filipovi'c, Ray P. Norris, Luke A. Barnes, James J. Condon

Abstract: We present MeerKAT L-band (886-1682 MHz) observations of the extended radio structure of the peculiar galaxy pair PKS 2130-538 known as the "Dancing Ghosts". The complex of bending and possibly interacting jets and lobes originate from two Active Galactic Nuclei hosts in the Abell 3785 galaxy cluster, one of which is the brightest cluster galaxy. The radio properties of the PKS 2130-538 flux density, spectral index and polarization - are typical for large, bent-tail galaxies. We also investigate a number of thin extended low surface brightness filaments originating from the lobes. Southeast from the Dancing Ghosts, we detect a region of low surface brightness emission that has no clear origin. While it could originate from the Abell 3785 radio halo, we investigate the possibility that it is a radio relic or emission associated with the two PKS 2130-538 hosts. We find no evidence of interaction between the two PKS 2130-538 hosts.

2.An analysis of the turbulence in the central region of M 42 (Orion Nebula) II: homogeneity and power-spectrum analyses

Authors:G. A. Anorve-Zeferino

Abstract: In this second communication we continue our analysis of the turbulence in the Huygens Region of the Orion Nebula (M 42). We calculate the associated transverse structure functions up to order 8-th and find that the higher-order transverse structure functions are almost proportional to the second-order transverse structure function: we find that after proper normalisation, the higher-order transverse structure functions only differ by very small deviations from the second-order transverse structure function in a sub-interval of the inertial range. We demonstrate that this implies that the turbulence in the Huygens Region is quasi-log-homogeneous, or to a better degree of approximation, binomially weighted log-homogeneous in the statistical sense, this implies that there is some type of invariant statistical structure in the velocity field of the Huygens Region. We also obtain and analyse the power-spectrum of the turbulent field and find that it displays a large tail that follows very approximately two power-laws, one of the form $E(k)\propto k^{-2.7}$ for the initial side of the tail, and one of the form $E(k)\propto k^{-1}$ for the end of the tail. We find that the power-law with exponent $\beta\sim -2.7$ corresponds to spatial scales of 0.0301--0.6450 pc. We find that the exponent of the first power-law $\beta\sim -2.7$ is related to the exponent $\alpha_2$ of the second-order structure function in the inertial range. We interpret the second power-law with exponent $\beta \sim -1$ as an indicator of viscous-dissipative processes occurring at scales of $\delta r=1$--5 pixels which correspond to spatial scales of 0.00043--0.00215 pc.

3.The Age-Metallicity Relation in the Solar Neighbourhood

Authors:S. Doner, S. Ak, O. Onal Tas, O. Plevne

Abstract: Age-metallicity relation for the Galactic disc is a crucial tool and to constrain the Galactic chemical evolution models. We investigate the age-metallicity relation of the Galactic disc using the red giant branch stars in the Solar neighbourhood. The data cover the Galactocentric radius of $7\leq R_{\rm gc} (\rm kpc) \leq9.5$, but extends up to 4 kpc in height from the Galactic plane. We use kinematic age derived from highly precise astrometric data of Gaia Data Release 2 and element abundance ratios from high-resolution spectroscopic data of APOGEE-2 catalogues. We apply a two-component Gaussian mixture model to chemically separate the programme stars into thin and thick disc populations. The stars in each population are grouped into different distance intervals from the Galactic plane. The mean metal abundances and velocity dispersions of the stars in the groups were calculated and the kinematic ages were determined from their kinematic parameters. We found a steep relation for the thin disc with -0.057$\pm$0.007 dex Gyr$^{-1}$, and even a steeper value of -0.103$\pm$0.009 dex Gyr$^{-1}$ for the thick disc. These age-metallicity relations along with the prominent differences in age, metallicity, and kinematic behaviours seen from the data, clearly show it is important to consider the distinct formation scenarios of the Galactic disc components in modelling the Milky Way.

1.FAST discovery of long tidal tails in NGC 4490/85

Authors:Yao Liu, Ming Zhu, Haiyang Yu, Mei Ai1, Peng Jiang, Siqi Liu, Lixia Yuan

Abstract: We report the discovery of a 100 kpc HI tail in the merging galaxy pair NGC 4490/85 detected by the Five-Hundred-meter Aperture Spherical radio Telescope (FAST). The tidal tails extended in both the south and north directions, and they are much longer than that reported previously based on the VLA interferometric maps. The NGC 4490/85 is surrounded by a large gas envelope, and a starburst low metallicity dwarf galaxy MAPS 1231+42 is found to be connected with the gas envelope, indicating that galaxy interaction trigged the intense star formation in it. Based on the fact that the metallicity in MAPS 1231+42 is one order of magnitude lower than that in the two disks of NGC 4490 and NGC 4485, we speculate that the gas near this galaxy should be primordial and could be due to gas inflow from the circum-galactic medium (CGM). We also found a collimated gas component pointing at a nearby dwarf galaxy KK 149, suggesting that this galaxy might also be interacting with the NGC 4490 pair. We discuss the possible origin of the long tidal tails and the extended gas envelope in this merging system based on the new data from FAST.

2.The survey of planetary nebulae in Andromeda (M31) VI. Kinematics of M31 inner-halo substructures and comparison with major-merger simulation predictions

Authors:Souradeep Bhattacharya, Magda Arnaboldi, Francois Hammer, Yanbin Yang, Ortwin Gerhard, Nelson Caldwell, Kenneth C. Freeman

Abstract: M31 has experienced a recent tumultuous merger history as evidenced from the many substructures that are still present in its inner halo, particularly the G1-Clump, NE- and W- shelves, and the Giant Stream (GS). We present planetary nebulae (PNe) line-of-sight velocity (LOSV) measurements covering the entire spatial extent of these four substructures. We further use predictions for the satellite and host stellar particle phase space distributions for a major merger (mass ratio = 1:4) simulation to help interpret the data. The measured PN LOSVs for the two shelves and GS are consistent with those from red giant branch stars. Their projected radius vs. LOSV phase space, links the formation of these substructures in a single unique event, consistent with a major merger. We find the G1-clump to be dynamically cold compared to the M31 disc ($\rm\sigma_{LOS, PN}=27$ km s$^{-1}$), consistent with pre-merger disc material. Such a structure can not form in a minor merger (mass ratio $\sim$1:20), and is therefore a smoking gun for the recent major merger event in M31. The simulation also predicts the formation of a predominantly in-situ halo from splashed-out pre-merger disc material, in qualitative agreement with observations of a metal-rich inner halo in M31. Juxtaposed with previous results for its discs, we conclude that M31 has had a recent (2.5 - 4 Gyr ago) `wet' major merger with the satellite falling along the GS, heating the pre-merger disc to form the M31 thicker disc, rebuilding the M31 thin disc, and creating the aforementioned inner-halo substructures.

3.Optical variability in Quasars: Scaling with black hole mass and Eddington ratio depend on the observed timescales

Authors:Patricia Arévalo, Paulina Lira, Paula Sánchez-Sáez, Priyanjali Patel, Elena López-Navas, Eugene Churazov, Lorena Hernández-García

Abstract: Quasars emission is highly variable, and this variability gives us clues to understand the accretion process onto supermassive black holes. We can expect variability properties to correlate with the main physical properties of the accreting black hole, i.e., its mass and accretion rate. It has been established that the relative amplitude of variability anti-correlates with the accretion rate.The dependence of the variance on black hole mass has remained elusive, and contradicting results, including positive, negative, or no correlation, have been reported. In this work, we show that the key to these contradictions lies in the timescales of variability studied (e.g., the length of the light curves available). By isolating the variance on different timescales as well as mass and accretion rate bins we show that there is indeed a negative correlation between black hole mass and variance and that this anti-correlation is stronger for shorter timescale fluctuations. The behavior can be explained in terms of a universal variability power spectrum for all quasars, resembling a broken power law where the variance is constant at low temporal frequencies and then drops continuously for frequencies higher than a characteristic frequency $f_b$, where $f_b$ correlates with the black hole mass. Furthermore, to explain all the variance results presented here, not only the normalization of this power spectrum must anti-correlate with the accretion rate, but also the shape of the power spectra at short timescales must depend on this parameter as well.

4.Analysis of the young open cluster Trumpler 2 using Gaia DR3 data

Authors:S. Tasdemir, T. Yontan

Abstract: We present an investigation of the open cluster Trumpler 2 using Gaia DR3 photometric, astrometric and spectroscopic data. 92 stars were identified as likely members of the cluster, with membership probabilities greater than 0.5. The mean proper-motion components of the cluster are derived as ($\mu_{\alpha}\cos \delta$, $\mu_{\delta}$)=($1.494 \pm 0.004$, $-5.386 \pm 0.005$) mas yr$^{-1}$. By comparing the Gaia based colour-magnitude diagram with the PARSEC isochrones scaled to $z=0.0088$, age, distance modulus and reddening are simultaneously estimated as $t=110 \pm 10$ Myr, $\mu=10.027 \pm0.149$ mag and $E(G_{\rm BP}-G_{\rm RP})=0.452\pm 0.019$ mag, respectively. The total mass of the cluster is estimated as 162 $M/M_{\odot}$ based on the stars with membership probabilities $P > 0$. The Mass function slope is derived to be $\Gamma = 1.33 \pm 0.13$ for Trumpler 2. This value is in a good agreement with that of of Salpeter. Galactic orbit analyses show that the Trumpler 2 orbits in a boxy pattern outside the solar circle and belongs to the young thin-disc component of the Galaxy.

5.Kinematics of stellar substructures in the Small Magellanic Cloud

Authors:Dalal El Youssoufi, Maria-Rosa L. Cioni, Nikolay Kacharov, Cameron P. M. Bell, Gal Matijević, Kenji Bekki, Richard de Grijs, Valentin D. Ivanov, Jacco Th. van Loon

Abstract: We present a kinematic analysis of the Small Magellanic Cloud using 3700 spectra extracted from the European Southern Observatory archive. We used data from Gaia and near-infrared photometry to select stellar populations and discard Galactic foreground stars. The sample includes main-sequence, red giant branch and red clump stars, observed with the Fibre Large Array Multi Wavelength Spectrograph. The spectra have a resolving power lambda/Delta(lambda) from 6500 to 38000. We derive radial velocities by employing a full spectrum fitting method using a penalised pixel fitting routine. We obtain a mean radial velocity for the galaxy of 159+/-2 km/s, with a velocity dispersion of 33+/-2 km/s. Our velocities agree with literature estimates for similar (young or old) stellar populations. The radial velocity of stars in the Wing and bar-like structure differ as a consequence of the dynamical interaction with the Large Magellanic Cloud. The higher radial velocity of young main-sequence stars in the bar compared to that of supergiants can be attributed to star formation around 40 Myr ago from gas already influenced by tidal stripping. Similarly, young main-sequence stars in the northern part of the bar, resulting from a prominent episode 25 Myr ago, have a higher radial velocity than stars in the southern part. Radial velocity differences between the northern and southern bar over densities are also traced by giant stars. They are corroborated by studies of the cold gas and proper motion indicating stretching/tidal stripping of the galaxy.

6.Hierarchical structure of the cosmic web and galaxy properties

Authors:Mariana Jaber, Marius Peper, Wojciech A. Hellwing, Miguel Angel Aragon-Calvo, Octavio Valenzuela

Abstract: Voids possess a very complex internal structure and dynamics. Using $N$-body simulations we study the hierarchical nature of sub-structures present in the cosmic web (CW). We use the SpineWeb method which provides a complete characterization of the CW into its primary constituents: voids, walls, filaments, and nodes. We aim to characterize the inner compositions of voids by detecting their internal filamentary structure and explore the impact of this on the properties of void galaxies. Using a semi-analytical galaxy evolution model we explore the impact of the CW on several galaxies' properties. We find the fraction of haloes living in various CW components to be a function of their mass, with the majority of the haloes of mass below $10^{12}M_{\odot}/h$, residing in voids and haloes of higher masses distributed mostly in walls. Similarly, in the Stellar-to-Halo mass relationship, we observe an environmental dependence for haloes of masses below $10^{12}M_{\odot}/h$, showing an increased stellar mass fraction for the densest environments. The spin is lower for galaxies in the densest environments for the mass range of $10^{10}-10^{12}M_{\odot}/h$. Finally, we found a strong trend of higher metallicity fractions for filaments and node galaxies, with respect to the full sample, in the range of $M_*<10^{10}M_{\odot}/h$. Our results show that cosmic voids possess an intricate internal network of substructures. This in turn makes them a complex environment for galaxy formation, impacting in an unique way the properties and evolution of the chosen few galaxies that form inside them.

1.Effect of the initial mass function on the dynamical SMBH mass estimate in the nucleated early-type galaxy FCC 47

Authors:Sabine Thater, Mariya Lyubenova, Katja Fahrion, Ignacio Martín-Navarro, Prashin Jethwa, Dieu D. Nguyen, Glenn van de Ven

Abstract: Supermassive black holes (SMBHs) and nuclear star clusters (NSCs) co-exist in many galaxies. While the formation history of the black hole is essentially lost, NSCs preserve their evolutionary history imprinted onto their stellar populations and kinematics. Studying SMBHs and NSCs in tandem might help us to ultimately reveal the build-up of galaxy centres. In this study, we combine large-scale VLT/MUSE and high-resolution adaptive-optics-assisted VLT/SINFONI observations of the early-type galaxy FCC 47 with the goal being to assess the effect of a spatially (non-)variable initial mass function (IMF) on the determination of the mass of the putative SMBH in this galaxy. We achieve this by performing DYNAMITE Schwarzschild orbit-superposition modelling of the galaxy and its NSC. In order to properly take account of the stellar mass contribution to the galaxy potential, we create mass maps using a varying stellar mass-to-light ratio derived from single stellar population models with fixed and with spatially varying IMFs. Using the two mass maps, we estimate black hole masses of $(7.1^{+0.8}_{-1.1})\times 10^7\,M_{\odot}$ and $(4.4^{+1.2}_{-2.1}) \times 10^7\,M_{\odot}$ at $3\sigma$ signifance, respectively. Compared to models with constant stellar-mass-to-light ratio, the black hole masses decrease by 15% and 48%, respectively. Therefore, a varying IMF, both in its functional form and spatially across the galaxy, has a non-negligible effect on the SMBH mass estimate. Furthermore, we find that the SMBH in FCC 47 has probably not grown over-massive compared to its very over-massive NSC.

2.Methanol formation through reaction of low energy $CH_{3}^{+}$ ions with an amorphous solid water surface at low temperature

Authors:Y. Nakai, W. M. C. Sameera, K. Furuya, H. Hidaka, A. Ishibashi, N. Watanabe

Abstract: We have performed experimental investigations of methanol formation via the reactions of low energy $CH_{3}^{+}$ ions with an amorphous solid water (ASW) surface around 10 K. A newly developed experimental apparatus enabled irradiation of the ASW surface by several eV ions and detection of trace amounts of reaction products on the surface. It was found that methanol molecules were produced by low-energy $CH_{3}^{+}$ irradiation of the ASW surface and that hydroxy groups in produced methanol originated from water molecules in ASW, as predicted in a previous theoretical study. Little temperature dependence of observed methanol intensity is apparent in the temperature range 12 - 60 K. Ab-initio molecular dynamics simulations under constant temperature conditions of 10 K suggested that this reaction spontaneously produced a methanol molecule and an $H_{3}O^{+}$ ion, regardless of the contact point of $CH_{3}^{+}$ on the ASW surface. We have performed simulation with an astrochemical model under molecular-cloud conditions, where the reaction between $CH_{3}^{+}$ and $H_{2}O$ ice, leading to methanol formation, was included. We found that the impact of the reaction on methanol abundance was limited only at the edge of the molecular cloud (< 1 mag) because of the low abundance of $CH_{3}^{+}$ in the gas phase, whereas the reaction between the abundant molecular ion $HCO^{+}$ and $H_{2}O$ ice, which has not yet been confirmed experimentally, can considerably affect the abundance of a complex organic molecule. This work sheds light on a new type of reaction between molecular ions and ice surfaces that should be included in astrochemical models.

3.Orientation of the spins of galaxies in the Local volume

Authors:I. D. Karachentsev, V. D. Zozulia

Abstract: We estimated the angular momentum, $J$, of $720$ galaxies in the Local Volume with distances $r < 12$ Mpc. The distribution of the average angular momentum along the Hubble sequence has a maximum at the morphological type $T= 4$ (Sbc), while the dispersion of the $J$-values for galaxies is minimal. Among the Local Volume population, 27 elite spiral galaxies stand out, with an angular momentum greater than 0.15 of the Milky Way, $J > 0.15 J_{MW}$, making the main contribution ($ > 90\%$) to the total angular momentum of galaxies in the considered volume. Using observational data on the kinematics and structure of these galaxies, we determined the direction of their spins. We present the first map of the distribution of the spins of 27 nearby massive spiral galaxies in the sky and note that their pattern does not exhibit significant alignment with respect to the Local Sheet plane. The relationship between the magnitude of the angular momentum and stellar mass of the local galaxies is well represented by a power law with an exponent of ($5/3$) over an interval of $6$ orders of magnitude of the mass of galaxies.

4.Uncovering the stellar structure of the dusty star-forming galaxy GN20 at z=4.055 with MIRI/JWST

Authors:L. Colina, A. Crespo Gómez, J. Álvarez-Márquez, A. Bik, F. Walter, L. Boogaard, A. Labiano, F. Peissker, P. Pérez-González, G. Östlin, T. R. Greve, H. U. Nørgaard-Nielsen, G. Wright, A. Alonso-Herrero, R. Azollini, K. I. Caputi, D. Dicken, M. García-Marín, J. Hjorth, O. Ilbert, S. Kendrew, J. P. Pye, T. Tikkanen, P. van der Werf, L. Costantin, E. Iani, S. Gillman, I. Jermann, D. Langeroodi, T. Moutard, P. Rinaldi, M. Topinka, E. F. van Dishoeck, M. Güdel, Th. Henning, P. O. Lagage, T. Ray, B. Vandenbussche

Abstract: Luminous infrared galaxies at high redshifts ($z$>4) include extreme starbursts that build their stellar mass over short periods of time (>100 Myr). These galaxies are considered to be the progenitors of massive quiescent galaxies at intermediate redshifts ($z\sim$2) but their stellar structure and buildup is unknown. Here, we present the first spatially resolved near-infrared imaging of GN20, one of the most luminous dusty star-forming galaxies known to date, observed at an epoch when the Universe was only 1.5 Gyr old. The 5.6$\mu$m image taken with the JWST Mid-Infrared Instrument (MIRI/JWST) shows that GN20 is a very luminous galaxy (M$_\mathrm{1.1\mu m,AB}$=$-$25.01), with a stellar structure composed of a conspicuous central source and an extended envelope. The central source is an unresolved nucleus that carries 9% of the total flux. The nucleus is co-aligned with the peak of the cold dust emission, and offset by 3.9 kpc from the ultraviolet stellar emission. The diffuse stellar envelope is similar in size to the clumpy CO molecular gas distribution. The centroid of the stellar envelope is offset by 1 kpc from the unresolved nucleus, suggesting GN20 is involved in an interaction or merger event supported by its location as the brightest galaxy in a proto-cluster. The stellar size of GN20 is larger by a factor of about 3-5 than known spheroids, disks, and irregulars at $z\sim$4, while its size and low S\'ersic index are similar to those measured in dusty, infrared luminous galaxies at $z\sim$2 of the same mass. GN20 has all the ingredients necessary for evolving into a massive spheroidal quiescent galaxy at intermediate $z$: it is a large, luminous galaxy at $z$=4.05 involved in a short and massive starburst centred in the stellar nucleus and extended over the entire galaxy, out to radii of 4 kpc, and likely induced by the interaction or merger with a member of the proto-cluster.

5.Planes of satellites in the nearby Universe

Authors:Oliver Müller

Abstract: Since the mid 70ies it is known that the dwarf galaxies around the Milky Way are arranged in a thin, polar structure. The arrangement and motion within this structure has been identified as a severe challenge to the standard model of cosmology, dubbed as the plane of satellites problem. More observational evidence for such structures has been put forward around other galaxies, such as the Andromeda galaxy, Cen\,A or NGC\,253, among others, adding to the previously identified tensions. Solutions to the plane of satellite problem should therefore not only be tailored to the Milky Way, but need to explain all these different observed systems and environments.

6.Merging galaxy clusters in IllustrisTNG

Authors:Ewa L. Lokas

Abstract: Mergers between galaxy clusters are an important stage in the formation of the large-scale structure of the Universe. Some of the mergers show a spectacular bow shock that formed as a result of recent passage of a smaller cluster through a bigger one, the classic example of this being the so-called bullet cluster. In this paper, I describe ten examples of interacting clusters identified among 200 of the most massive objects, with total masses above $1.4 \times 10^{14}$ M$_{\odot}$, from the IllustrisTNG300 simulation by searching for prominent bow shocks in their temperature maps. Despite different mass ratios of the two merging clusters, the events are remarkably similar in many respects. In all cases, the companion cluster passed close to the main one only once, between 0.9 and 0.3 Gyr ago, with the pericenter distance of 100-530 kpc and a velocity of up to 3400 km s$^{-1}$. The subcluster, typically an order of magnitude smaller in mass than the main cluster before the interaction, loses most of its dark matter and gas in the process. The displacement between the collisionless part of the remnant and the bow shock is such that the remnant typically lags behind the shock or coincides with it, with a single exception of the merger occurring with the largest velocity. Usually about 1% of the gas cells in the merging clusters are shocked, and the median Mach numbers of these gas cells are around two. Due to the relatively small size of the simulation box, no close analog of the bullet cluster was found, but I identified one case that is similar in terms of mass, velocity, and displacement. The presented cases bear more resemblance to less extreme observed interacting clusters such as A520 and Coma.

7.High Resolution Observations of HI in the IC 63 Reflection Nebula

Authors:L. Bonne, B-G Andersson, R. Minchin, A. Soam, J. Yaldaei, K. Kulas, J. Karoly, L. B. G. Knee, S. Kumar, N. Roy

Abstract: Photodissociation regions (PDRs), where the (far-)ultraviolet light from hot young stars interact with the gas in surrounding molecular clouds, provide laboratories for understanding the nature and role of feedback by star formation on the interstellar medium. While the general nature of PDRs is well understood - at least under simplified conditions - the detailed dynamics and chemistry of these regions, including gas clumping, evolution over time etc. can be very complex. We present interferometric observations of the 21 cm atomic hydrogen line, combined with [CII] 158 $\mu$m observations, towards the nearby reflection nebula IC 63. We find a clumpy HI structure in the PDR, and a ring morphology for the HI emission at the tip of IC 63. We further unveil kinematic substructure, of the order of 1~km~s$^{-1}$, in the PDR layers and several legs that will disperse IC 63 in $<$0.5 Myr. We find that the dynamics in the PDR explain the observed clumpy HI distribution and lack of a well-defined HI/H$_{2}$ transition front. However, it is currently not possible to conclude whether HI self-absorption (HISA) and non-equilibrium chemistry also contribute to this clumpy morphology and missing HI/H$_{2}$ transition front.

8.The slippery slope of dust attenuation curves: Correlation of dust attenuation laws with star-to-dust compactness up to z = 4

Authors:M. Hamed, K. Małek, V. Buat, Junais, L. Ciesla, D. Donevski, G. Riccio, M. Figueira

Abstract: Aims. We investigate dust attenuation of 122 heavily dust-obscured galaxies detected with the Atacama Large Millimeter Array (ALMA) and Herschel in the COSMOS field. We search for correlations between dust attenuation recipes and the variation of physical parameters, mainly the effective radii of galaxies, their star formation rates (SFR), and stellar masses, and aim to understand which of the commonly used laws best describes dust attenuation in dusty star-forming galaxies at high redshift. Methods. We make use of the extensive photometric coverage of the COSMOS data combined with highly-resolved dust continuum maps from ALMA. We use CIGALE to estimate various physical properties of these dusty objects, mainly their SFR, their stellar masses and their attenuation. We infer galaxy effective radii (Re) using GALFIT in the Y band of HSC and ALMA continuum maps. We use these radii to investigate the relative compactness of the dust continuum and the extension of the rest-frame UV/optical Re(y)/Re(ALMA). Results. We find that the physical parameters calculated from our models strongly depend on the assumption of dust attenuation curve. As expected, the most impacted parameter is the stellar mass, which leads to a change in the "starburstiness" of the objects. We find that taking into account the relative compactness of star-to-dust emission prior to SED fitting is crucial, especially when studying dust attenuation of dusty star-forming galaxies. Shallower attenuation curves did not show a clear preference of compactness with attenuation, while the Calzetti attenuation curve preferred comparable spatial extent of unattenuated stellar light and dust emission. The evolution of the Re(UV)/Re(ALMA) ratio with redshift peeks around the cosmic noon in our sample of DSFGs, showing that this compactness is correlated with the cosmic SFR density of these dusty sources.

9.EPOCHS Paper II: The Ultraviolet Luminosity Function from z between 7.5 and 13.5 using 110 square arcminutes of deep, blank-field data from the PEARLS Survey and Public Science Programmes

Authors:Nathan J. Adams, Christopher J. Conselice, Duncan Austin, Thomas Harvey, Leonardo Ferreira, James Trussler, Ignas Juodzbalis, Qiong Li, Rogier Windhorst, Seth H. Cohen, Rolf Jansen, Jake Summers, Scott Tompkins, Simon P. Driver, Aaron Robotham, Jordan C. J. D'Silva, Haojing Yan, Dan Coe, Brenda Frye, Norman A. Grogin, Anton M. Koekemoer, Madeline A. Marshall, Nor Pirzkal, Russell E. Ryan, Jr., W. Peter Maksym, Michael J. Rutkowski, Christopher N. A. Willmer, Heidi B. Hammel, Mario Nonino, Rachana Bhatawdekar, Stephen M. Wilkins, Steven P. Willner, Larry D. Bradley, Tom Broadhurst, Cheng Cheng, Herve Dole, Nimish P. Hathi, Adi Zitrin

Abstract: We present an analysis of the ultraviolet luminosity function (UV LF) and star formation rate density of distant galaxies ($7.5 < z < 13.5$) in the `blank' fields of the Prime Extragalactic Areas for Reionization Science (PEARLS) survey combined with Early Release Science (ERS) data from the CEERS, GLASS and NGDEEP surveys/fields. We use a combination of SED fitting tools and quality cuts to obtain a reliable selection and characterisation of high-redshift ($z>6.5$) galaxies from a consistently processed set of deep, near-infrared imaging. Within an area of 110 arcmin$^{2}$, we identify 214 candidate galaxies at redshifts $z>6.5$ and we use this sample to study the ultraviolet luminosity function (UV LF) in four redshift bins between $7.5<z<13.5$. The measured number density of galaxies at $z=8$ and $z=9$ match those of past observations undertaken by the em Hubble Space Telescope (HST). However, towards higher redshifts we find that the evolution of the UV LF is mild, resulting in higher measured number densities of UV luminous galaxies at $z=10.5$ and $z=12.5$ compared to predictions from simulations and past HST observations. When examining the star formation rate density of galaxies at this time period, our observations are still consistent with a constant star formation efficiency, are slightly lower than previous early estimations using JWST and support galaxy driven reionization at $z\sim8$.

1.Dynamical complexity in micro-scale disk-wind systems

Authors:Fabrizio Fiore, Massimo Gaspari, Alfredo Luminari, Paolo Tozzi, Lucilla De Arcangelis

Abstract: Powerful winds at accretion disk scales have been observed in the past 20 years in many AGN, the so called Ultra-Fast Outflows (UFOs). Outflows are intimately related to mass accretion due to the conservation of angular momentum, and therefore are a key ingredient of most accretion disk models around BHs. At the same time, nuclear winds and outflows can provide the feedback which regulates the joint BH and galaxy growth. We reconsider UFO observations in the framework of the Magneto-Hydrodynamic Disk Wind (MHDW) scenario and study their statistical properties. We derive the typical wind-activity history in our sources by assuming that it can be statistically described by population functions. We study the statistical properties of UFOs from the literature and derive the distribution functions of the ratio $\bar \omega$ between the mass outflow and inflow rates, and the ratio $\lambda_w$ between the mass outflow and the Eddington accretion rates. We study the links between $\bar \omega$ and $\lambda_w$ and the Eddington ratio $\lambda={L_{bol}}/{L_{Edd}}$. We find that the distribution functions of $\bar \omega$ and $\lambda_w$ can be described as power laws above some threshold, suggesting that there may be many wind sub-events for each major wind event in each AGN activity cycle, which is a fractal behaviour in agreement with current MHDW and Chaotic Cold Accretion theories. We then introduce a simple cellular automaton to investigate how the dynamical properties of an idealized disk-wind system changes following the introduction of simple feedback rules. We find that without feedback the system is over-critical. Conversely, if feedback is present, the system can be driven toward self organized criticality. Our results corroborate the hypothesis that AGN feedback is a necessary key ingredient in disk-wind systems, and thus, in shaping the co-evolution of galaxies and supermassive BHs.

2.Modeling Two First Hydrostatic Core Candidates Barnard 1b-N and 1b-S

Authors:Hao-Yuan Duan, Shih-Ping Lai, Naomi Hirano, Travis J. Thieme

Abstract: A first hydrostatic core (FHC) is proposed to form after the initial collapse of a prestellar core, as a seed of a Class 0 protostar. FHCs are difficult to observe because they are small, compact, embedded, and short lived. In this work, we explored the physical properties of two well-known FHC candidates, B1-bN and B1-bS, by comparing interferometric data from Submillimeter Array (SMA) 1.1 and 1.3 mm and Atacama Large Millimeter/submillimeter Array (ALMA) 870 $\mu$m observations with simulated synthesis images of the two sources. The simulated images are based on a simple model containing a single, hot compact first-core-like component at the center surrounded by a large-scale, cold and dusty envelope described by a broken power-law density distribution with an index, $\alpha$. Our results show that the hot compact components of B1-bN and B1-bS can be described by temperatures of \sim 500 K with a size of \sim 4 au, which are in agreement with theoretical predictions of an FHC. If the $\alpha$ inside the broken radii is fixed to -1.5, we find $\alpha$ \sim -2.9 and \sim -3.3 outside the broken radii for B1-bN and B1-bS, respectively, consistent with theoretical calculations of a collapsing, bounded envelope and previous observations. Comparing the density and temperature profiles of the two sources with radiation-hydrodynamic simulations of an FHC, we find both sources lie close to, but before, the second collapse stage. We suggest that B1-bS may have started the collapsing process earlier compared to B1-bN, since a larger discontinuity point is found in its density profile.

3.Integral Field Spectroscopy of the Cometary Starburst Galaxy NGC 4861

Authors:Nathan Roche, José M. Vílchez, Jorge Iglesias-Páramo, Polychronis Papaderos, Sebastian F. Sánchez, Carolina Kehrig, Salvador Duarte Puertas

Abstract: Using the PMAS Integral Field Unit on the Calar Alto 3.5m telescope we observed the southern component (Markarian 59) of the `cometary' starburst galaxy NGC 4861. Mrk 59 is centred on a giant nebula and concentration of stars 1 kpc in diameter. Strong $\rm H\alpha$ emission points to a star-formation rate (SFR) at least 0.47 $\rm M_{\odot}yr^{-1}$. Mrk 59 has a very high [OIII]$\rm\lambda5007/H\beta$ ratio, reaching 7.35 in the central nebula, with a second peak at a star-forming hotspot further north. Fast outflows are not detected but nebular motion and galaxy rotation produce relative velocities up to 40 km $\rm s^{-1}$. Spectral analysis of different regions with `Fitting Analysis using Differential evolution Optimisation' (FADO) finds that the stars in the central and `spur' nebulae are very young, $\rm \leq125~Myr$ with a large $\rm <10~Myr$ contribution. Older stars ($\rm \sim 1~Gyr$), make up the northern disk component, while the other regions show mixtures of 1 Gyr age with very young stars. This and the high specific SFR $\rm\sim 3.5~Gyr^{-1}$ imply a bimodal star formation history, with Mrk 59 formed in ongoing starbursts fuelled by a huge gas inflow, turning the galaxy into an asymmetric `green pea' or blue compact dwarf. We map the HeII$\lambda4686$ emission, and identify a broad component from the central nebula, consistent with the emission of $\sim 300$ Wolf-Rayet stars. About a third of the HeII$\lambda$4686 flux is a narrow line emitted from a more extended area covering the central and spur nebulae, and may have a different origin.

4.Europium enrichment and hierarchical formation of the Galactic halo

Authors:L. Cavallo, G. Cescutti, F. Matteucci

Abstract: Context. The origin of the large star-to-star variation of the [Eu/Fe] ratios observed in the extremely metal-poor (at [Fe/H]$\leq-3$) stars of the Galactic halo is still a matter of debate.\\ Aims. In this paper, we explore this problem by putting our stochastic chemical evolution model in the hierarchical clustering framework, with the aim of explaining the observed spread in the halo.\\ Methods. We compute the chemical enrichment of Eu occurring in the building blocks that have possibly formed the Galactic halo. In this framework, the enrichment from neutron star mergers can be influenced by the dynamics of the binary systems in the gravitational potential of the original host galaxy. In the least massive systems, the neutron stars can merge outside the host galaxy and so only a small fraction of newly produced Eu can be retained by the parent galaxy itself.\\ Results. In the framework of this new scenario, the accreted merging neutron stars are able to explain the presence of stars with sub-solar [Eu/Fe] ratios at [Fe/H]$\leq-3$, but only if we assume a delay time distribution for merging of the neutron stars $\propto t^{-1.5}$. We confirm the correlation between the dispersion of [Eu/Fe] at a given metallicity and the fraction of massive stars which give origin to neutron star mergers. The mixed scenario, where both neutron star mergers and magneto-rotational supernovae do produce Eu, can explain the observed spread in the Eu abundance also for a delay time distribution for mergers going either as $\propto t^{-1}$ or $\propto t^{-1.5}$.

5.Angular momentum variation of the Milky Way thick disk: The dependence of chemical abundance and the evidence on inside-out formation scenario

Authors:Guozhen Hu, Zhengyi Shao, Lu Li

Abstract: We investigate the angular momentum of mono-abundance populations (MAPs) of the Milky Way thick disk by using a sample of 26,076 giant stars taken from APOGEE DR17 and Gaia EDR3. The vertical and perpendicular angular momentum components, $L_Z$ and $L_P$, of MAPs in narrow bins have significant variations across the [$\alpha$/M]-[M/H] plane. $L_Z$ and $L_P$ systematically change with [M/H] and [$\alpha$/M] and can be alternatively quantified by the chemical gradients: $d[{\rm M/H}]/dL_Z = 1.2\times 10^{-3} $\,dex\,kpc$^{-1}$\,km$^{-1}$\,s, $d{\rm [M/H]}/dL_P = -5.0\times 10^{-3}$\,dec\,kpc$^{-1}$\,km$^{-1}$\,s, and $d[\alpha/{\rm M}]/dL_Z = -3.0\times 10^{-4} $\,dex\,kpc$^{-1}$\,km$^{-1}$\,s, $d[\alpha/{\rm M}]/dL_P = 1.2\times 10^{-3}$\,dec\,kpc$^{-1}$\,km$^{-1}$\,s. These correlations can also be explained as the chemical-dependence of the spatial distribution shape of MAPs. We also exhibit the corresponding age dependence of angular momentum components. Under the assumption that the guiding radius ($R_g$) is proportional to $L_Z$, it provides direct observational evidence of the inside-out structure formation scenario of the thick disk, with $dR_g/dAge = -1.9$\,kpc\,Gyr$^{-1}$. The progressive changes in the disk thickness can be explained by the upside-down formation or/and the consequent kinematical heating.

6.The Calar Alto Legacy Integral Field Area Survey: extended and remastered data release

Authors:S. F. Sanchez, L. Galbany, C. J. Walcher, R. Garcia-Benito, J. K. Barrera-Ballesteros

Abstract: This paper describes the extended data release of the Calar Alto Legacy Integral Field Area (CALIFA) survey (eDR). It comprises science-grade quality data for 895 galaxies obtained with the PMAS/PPak instrument at the 3.5 m telescope at the Calar Alto Observatory along the last 12 years, using the V500 setup (3700-7500{\AA}, 6{\AA}/FWHM) and the CALIFA observing strategy. It includes galaxies of any morphological type, star-formation stage, a wide range of stellar masses ($\sim$10$^7$ 10$^{12}$ Msun ), at an average redshift of $\sim$0.015 (90\% within 0.005$<$z$<$0.05). Primarily selected based on the projected size and apparent magnitude, we demonstrate that it can be volume corrected resulting in a statistically limited but representative sample of the population of galaxies in the nearby Universe. All the data were homogeneous re-reduced, introducing a set of modifications to the previous reduction. The most relevant is the development and implementation of a new cube-reconstruction algorithm that provides with an (almost) seeing-limited spatial resolution (FWHM PSF $\sim$1.0").To illustrate the usability and quality of the data, we extracted two aperture spectra for each galaxy (central 1.5" and fully integrated), and analyze them using pyFIT3D. We obtain a set of observational and physical properties of both the stellar populations and the ionized gas, that have been compared for the two apertures, exploring their distributions as a function of the stellar masses and morphologies of the galaxies, comparing with recent results in the literature. DATA RELEASE: http://ifs.astroscu.

1.Radio Polarization: A Powerful Resource for Understanding the Blazar Divide

Authors:Janhavi Baghel, P. Kharb, Silpa S., Luis C. Ho, C. M. Harrison

Abstract: With high-sensitivity kiloparsec-scale radio polarimetry, we can examine the jet-medium interactions and get a better understanding of the blazar divide in radio-loud (RL) AGN. We are analyzing the radio polarimetric observations with the EVLA and GMRT of 24 quasars and BL Lacs belonging to the Palomar-Green (PG) sample. The RL quasars show extensive polarisation structures in their cores, jets, lobes, and hotspots, whereas preliminary results suggest that BL Lacs exhibit polarisation primarily in their cores and inner jet regions. These findings imply that both intrinsic (central engine-related) and extrinsic (environment-related) variables are important in the formation of the blazar subclasses. The Fanaroff-Riley (FR) dichotomy can also be studied assuming RL unification and looking through the lens of blazars. Due to the radio-unbiased nature of the optically/UV-selected PG sample, we find a large fraction of the PG quasars are restarted, distorted (S- or X-shaped), or have a hybrid FR morphology.

2.Confirmation of the standard cosmological model from red massive galaxies $\sim600$ Myr after the Big Bang

Authors:Francisco Prada, Peter Behroozi, Tomoaki Ishiyama, Anatoly Klypin, Enrique Pérez

Abstract: In their recent study, Labb\'e et al. used multi-band infrared images captured by the James Webb Space Telescope (JWST) to discover a population of red massive galaxies that formed approximately 600 million years after the Big Bang. The authors reported an extraordinarily large density of these galaxies, with stellar masses exceeding $10^{10}$ solar masses, which, if confirmed, challenges the standard cosmological model as suggested by recent studies. However, this conclusion is disputed. We contend that during the early epochs of the universe the stellar mass-to-light ratio could not have reached the values reported by Labb\'e et al. A model of galaxy formation based on standard cosmology provides support for this hypothesis, predicting the formation of massive galaxies with higher ultraviolet (UV) luminosity, which produce several hundred solar masses of stars per year and containing significant dust. These forecasts are consistent with the abundance of JWST/HST galaxies selected photometrically in the rest-frame UV wavelengths and with the properties of the recent spectroscopically-confirmed JWST/HST galaxies formed during that era. Discrepancies with Labb\'e et al. may arise from overestimation of the stellar masses, systematic uncertainties, absence of JWST/MIRI data, heavy dust extinction affecting UV luminosities, or misidentification of faint red AGN galaxies at closer redshifts. The current JWST/HST results, combined with a realistic galaxy formation model, provide strong confirmation of the standard cosmology.

3.Vorticity and magnetic dynamo from subsonic expansion waves

Authors:Albert Elias-López, Fabio Del Sordo, Daniele Viganò

Abstract: This work concentrates on the effect of an irrotational forcing on a magnetized flow in the presence of rotation, baroclinicity, shear, or a combination of them. By including magnetic field in the model we can evaluate the occurrence of dynamo on both small and large scales. We aim at finding what are the minimum ingredients needed to trigger a dynamo instability and what is the relation between dynamo and the growth of vorticity. We use the Pencil code to run resistive MHD direct numerical simulations. We report no dynamo in all cases where only rotation is included, regardless on the equation of state. Conversely, the inclusion of a background sinusoidal shearing profile leads to an hydrodynamic instability that produces an exponential growth of the vorticity at all scales, starting from small ones. This is know as vorticity dynamo. The onset of this instability occurs after a rather long temporal evolution of several thousand turbulent turnover times. The vorticity dynamo in turn drives an exponential growth of the magnetic field, first at small scales, then also at large one. The instability then saturates and the magnetic field approximately reaches equipartition with the turbulent kinetic energy. During the saturation phase we can observe a winding of the magnetic field in the direction of the shearing flow. By varying the intensity of the shear we see that the growth rates of this instability change. The inclusion of the baroclinic term delays the onset of the vorticity dynamo but leads to a more rapid growth. We demonstrate how in the presence of shear, even a purely irrotational forcing amplifies the field to equipartition. At the same time, we confirm how this forcing alone does not lead to vorticity nor magnetic field growth, and this picture does not change in the presence of rotation or baroclinicity up to $256^3$ meshpoints.

4.A 3D view of dwarf galaxies with Gaia and VLT/FLAMES I. The Sculptor dwarf spheroidal

Authors:Eline Tolstoy, Ása Skúladóttir, Giuseppina Battaglia, Anthony G. A. Brown, Davide Massari, Michael J. Irwin, Else Starkenburg, Stefania Salvadori, Vanessa Hill, Pascale Jablonka, Maurizio Salaris, Thom van Essen, Carla Olsthoorn, Amina Helmi, John Pritchard

Abstract: We present a new homogeneous survey of VLT/FLAMES LR8 line-of-sight radial velocities (vlos) for 1604 resolved red giant branch stars in the Sculptor dwarf spheroidal galaxy. In addition, we provide reliable Ca II triplet metallicities, [Fe/H], for 1339 of these stars. From this combination of new observations (2257 individual spectra) with ESO archival data (2389 spectra), we obtain the largest and most complete sample of vlos and [Fe/H] measurements for individual stars in any dwarf galaxy. Our sample includes VLT/FLAMES LR8 spectra for 55% of the red giant branch stars at G $<20$ from Gaia DR3, and $>70$% of the brightest stars, G $<18.75$. Our spectroscopic velocities are combined with Gaia DR3 proper motions and parallax measurements for a new and more precise membership analysis. We look again at the global characteristics of Sculptor, deriving a mean metallicity of $\langle$[Fe/H]$\rangle = -1.82 \pm 0.45$ and a mean line-of-sight velocity of $\langle$vlos$\rangle = +111.2 \pm 0.25$km/s. There is a clear metallicity gradient in Sculptor, -0.7deg/dex, with the most metal-rich population being the most centrally concentrated. Furthermore, the most metal-poor population in Sculptor, [Fe/H]$<-2.5$, appears to show kinematic properties distinct from the rest of the stellar population. Finally, we combine our results with the exquisite Gaia DR3 multi-colour photometry to further investigate the colour-magnitude diagram of the resolved stellar population in Sculptor. Our detailed analysis shows a similar global picture as previous studies, but with much more precise detail, revealing that Sculptor has more complex properties than previously thought. This survey emphasises the role of the stellar spectroscopy technique and this galaxy as a benchmark system for modelling galaxy formation and evolution on small scales.

5.Rotational spectroscopy of oxirane-\textit{2,2}-$d_2$, $c$-CD$_2$CH$_2$O, and its tentative detection toward IRAS 16293$-$2422~B

Authors:Holger S. P. Müller, Jes K. Jørgensen, Jean-Claude Guillemin, Frank Lewen, Stephan Schlemmer

Abstract: We prepared a sample of oxirane doubly deuterated at one C atom and studied its rotational spectrum in the laboratory for the first time between 120~GHz and 1094~GHz. Accurate spectroscopic parameters up to eighth order were determined, and the calculated rest frequencies were used to identify $c$-CD$_2$CH$_2$O tentatively in the interstellar medium in the Atacama Large Millimeter/submillimeter Array Protostellar Interferometric Line Survey (PILS) of the Class 0 protostellar system IRAS 16293$-$2422. The $c$-CD$_2$CH$_2$O to $c$-C$_2$H$_4$O ratio was estimated to be $\sim$0.054 with $T_{\rm rot} = 125$ K. This value translates to a D-to-H ratio of $\sim$0.16 per H atom which is higher by a factor of 4.5 than the $\sim$0.036 per H atom obtained for $c$-C$_2$H$_3$DO. Such increase in the degree of deuteration referenced to one H atom in multiply deuterated isotopologs compared to their singly deuterated variants have been observed commonly in recent years.

6.Nuclear activity in z less than 0.3 QSO 2's mainly triggered by galaxy mergers

Authors:Bruna L. C. Araujo, Thaisa Storchi-Bergmann, Sandro B. Rembold, André L. P. Kaipper, Bruno Dall'Agnol de Oliveira

Abstract: We investigate the role of the close environment on the nuclear activity of a sample of 436 nearby ($z<0.3$) QSO 2's -- selected from SDSS-III spectra, via comparison of their environment and interaction parameters with those of a control sample of 1308 galaxies. We have used the corresponding SDSS images to obtain the number of neighbour galaxies $N$, tidal strength parameter $Q$ and asymmetry parameters. We find a small excess of $N$ in the QSOs compared to its three controls, and no difference in $Q$. The main difference is an excess of asymmetry in the QSOs hosts, which is almost twice that of the control galaxies. This difference is not due to the hosts' morphology, since there is no difference in their Galaxy Zoo classifications. HST images of two highly asymmetric QSO 2 hosts of our sample show that both sources have a close companion (at projected separations $\sim$ 5 kpc), which we thus conclude is the cause of the observed asymmetry in the lower resolution SDSS images. The mean projected radius of the controls is $ \langle r \rangle = 8.53\pm$0.06 kpc, while that of the QSO hosts is $ \langle r \rangle = 9.39\pm$0.12 kpc, supporting the presence of interaction signatures in the outer regions of the QSO hosts. Our results favour a scenario in which nuclear activity in QSO 2's is triggered by close galaxy interactions -- when the distance between the host and companion is of the order of the galaxy radius, implying that they are already in the process of merger.

7.Photometric determination of the mass accretion rates of pre-main-sequence stars. VIII. Recent star formation in NGC 299

Authors:Marissa Vlasblom, Guido De Marchi

Abstract: We studied the properties of the young stellar populations in the NGC 299 cluster in the Small Magellanic Cloud using observations obtained with the Hubble Space Telescope in the $V, I$, and $H\alpha$ bands. We identified 252 stars with H$\alpha$ excess exceeding 5 $\sigma$ and an equivalent width of the H$\alpha$ emission line of at least 20 \r{A}, indicating that these stars are still undergoing accretion and therefore represent bona fide pre-main-sequence (PMS) objects. For all of them, we derived the mass, age, and mass accretion rate by comparing the observed photometry with theoretical models. We find evidence for the existence of two populations of PMS stars, with median ages of 25 and 50 Myr respectively. The average mass accretion rate for these PMS stars is $\sim 5 \times 10^{-9}$ M$_\odot$ yr$^{-1}$, which is comparable to the values found in other low-metallicity, low-density clusters in the Magellanic Clouds, but is about a factor of three lower than those measured for stars of similar mass and age in denser Magellanic Cloud stellar regions. Our findings support the hypothesis that both the metallicity and density of the forming environment can affect the mass accretion rate and thus the star formation process in a region. A study of the spatial distribution of both massive stars and (low-mass) PMS objects reveals that the former are clustered near the nominal centre of NGC 299, whereas the PMS stars are rather uniformly distributed over the field. To explore whether the stars formed in an initially more diffuse or compact structure, we studied the cluster's stellar density profile. We find a core radius $r_c\simeq 0.6$ pc and a tidal radius $r_t\simeq 5.5$ pc, with an implied concentration parameter $c \simeq 1$, suggesting that the cluster could be dispersing into the field.

8.Constraints on the Galactic Centre environment from \textit{Gaia} hypervelocity stars III: Insights on a possible companion to Sgr A*

Authors:Fraser A. Evans, Alexander Rasskazov, Amber Remmelzwaal, Tommaso Marchetti, Alfred Castro-Ginard, Elena Maria Rossi, Jo Bovy

Abstract: We consider a scenario in which Sgr A* is in a massive black hole binary (MBHB) with an as-of-yet undetected supermassive or intermediate-mass black hole companion. Dynamical encounters between this MBHB and single stars in its immediate vicinity would eject hypervelocity stars (HVSs) with velocities beyond the Galactic escape velocity. In this work, we use existing HVS observations to constrain for the first time the existence of a companion to Sgr A*. We simulate the ejection of HVSs via the `MBHB slingshot' scenario and show that the population of HVSs detectable today depends strongly on the companion mass and the separation of the MBHB. We demonstrate that the lack of uncontroversial HVS candidates in \textit{Gaia} Data Release 3 places a firm upper limit on the mass of a possible Sgr A* companion. Within one milliparsec of Sgr A*, our results exclude a companion more massive than $1000 \, \mathrm{M_\odot}$. If Sgr A* recently merged with a companion black hole, our findings indicate that unless this companion was less massive than $500 \, \mathrm{M_\odot}$, this merger must have occurred at least $10$ Myr ago. These results complement and improve upon existing independent constraints on a companion to Sgr A* and show that large regions of its parameter space can now be ruled out.

9.Evolution of open clusters with or without black holes

Authors:B. Shukirgaliyev, P. Berczik, A. Otebay, M. Kalambay, A. Kamlah, Y. Tleukhanov, E. Abdikamalov, S. Banerjee, A. Just

Abstract: Binary black holes (BHs) can be formed dynamically in the centers of star clusters. The high natal kicks for stellar-mass BHs used in previous works made it hard to retain BHs in star clusters. Recent studies of massive star evolution and supernovae (SN) propose kick velocities that are lower due to the fallback of the SN ejecta. We study the impact of these updates by performing $N$-body simulations following instantaneous gas expulsion. For comparison, we simulate two additional model sets with the previous treatment of stars: one with high kicks and another with artificial removal of the kicks. Our model clusters initially consist of about one hundred thousand stars, formed with centrally-peaked efficiency. We find that the updated treatment of stars, due to the fallback-scaled lower natal kicks, allows clusters to retain SN remnants after violent relaxation. The mass contribution of the retained remnants does not exceed a few percent of the total bound cluster mass during the early evolution. For this reason, the first giga year of evolution is not affected significantly by this effect. Nevertheless, during the subsequent long-term evolution, the retained BHs accelerate mass segregation, leading to the faster dissolution of the clusters.

1.Photometric metallicity for 694233 Galactic giant stars from Gaia DR3 synthetic Stromgren photometry. Metallicity distribution functions of halo sub-structures

Authors:Bellazzini M. INAF-OAS Bo, Massari D. INAF-OAS Bo, De Angeli F. IoA - Cambridge, Mucciarelli A. DIFA - UniBo, Bragaglia. A INAF-OAS Bo, Riello M. IoA - Cambridge, Montegriffo P. INAF-OAS Bo

Abstract: We use the calibrations by Calamida et al. and by Hilker et al., and the standardised synthetic photometry in the v, b, and y Stromgren passbands from Gaia DR3 BP/RP spectra, to obtain photometric metallicities for a selected sample of 694233 old Galactic giant stars having |b|>20.0 and parallax uncertainties lower than 10%. The zero point of both sets of photometric metallicities has been shifted to to ensure optimal match with the spectroscopic [Fe/H] values for 44785 stars in common with APOGEE DR17, focusing on the metallicity range where they provide the highest accuracy. The metallicities derived in this way from the Calamida et al. calibration display a typical accuracy of ~0.1 dex and 1 sigma precision ~0.2 dex in the range -2.2 <=[Fe/H]<= -0.4, while they show a systematic trend with [Fe/H] at higher metallicity, beyond the applicability range of the relation. Those derived from the Hilker et al. calibration display, in general, worse precision, and lower accuracy in the metal-poor regime, but have a median accuracy < 0.05 dex for [Fe/H]>= -0.8. These results are confirmed and, consequently, the metallicities validated, by comparison with large sets of spectroscopic metallicities from various surveys. The newly obtained metallicities are used to derive metallicity distributions for several previously identified sub-structures in the Galactic halo with an unprecedented number of stars. The catalogue including both sets of metallicities and the associated uncertainties is made publicly available.

2.Properties of the dense cores and filamentary structures in the Vela C molecular cloud

Authors:Xue-Mei Li, Guo-Yin Zhang, Alexander Men'shchikov, Jin-Zeng Li, Chang Zhang, Zhong-Zu Wu

Abstract: The initial and boundary conditions of the Galactic star formation in molecular clouds are not well understood. In an effort to shed new light on this long-standing problem, we measured properties of dense cores and filamentary structures in the Vela C molecular cloud, observed with Herschel. We applied the getsf extraction method to separate the components of sources and filaments from each other and their backgrounds, before detecting, measuring, and cataloging the structures. The cores and filamentary structures constitute 40% of the total mass of Vela C, most of the material is in the low-density molecular background cloud. We selected 570 reliable cores, of which 149 are the protostellar cores and 421 are the starless cores. Almost 78% of the starless cores were identified with the gravitationally bound prestellar cores. The exponent of the CMF (alpha = 1.35) is identical to that of the Salpeter IMF. We selected 68 filaments with at least one side that appeared not blended with adjacent structures. The filament widths are in the range of 0.15 pc to 0.63 pc, and have a median value of W = 0.3(0.11) pc. The surface densities of filaments are well correlated with their contrasts and linear densities. Within uncertainties of the filament instability criterion, many filaments may well be both supercritical and subcritical. A large fraction of filaments may definitely be considered supercritical, in which are found 94 prestellar cores, 83 protostellar cores, and only 1 unbound starless core. Taking into account the uncertainties, the supercritical filaments contain only prestellar and protostellar cores. Our findings support the idea that there exists a direct relationship between the CMF and IMF and that filaments play a key role in the formation of prestellar cores, which is consistent with the previous Herschel results.

3.Multi-epoch hard X-ray view of Compton-thick AGN Circinus Galaxy

Authors:Abhijit Kayal, Veeresh Singh, Claudio Ricci, N. P. S. Mithun, Santosh Vadawale, Gulab Dewangan, Poshak Gandhi

Abstract: The circumnuclear material around Active Galactic Nuclei (AGN) is one of the essential components of the obscuration-based unification model. However, our understanding of the circumnuclear material in terms of its geometrical shape, structure and its dependence on accretion rate is still debated. In this paper, we present the multi-epoch broadband X-ray spectral modelling of a nearby Compton-thick AGN in Circinus galaxy. We utilise all the available hard X-ray ($> 10$ keV) observations taken from different telescopes, $i.e.,$ $BeppoSAX$, $Suzaku$, $NuSTAR$ and $AstroSat$, at ten different epochs across $22$ years from $1998$ to $2020$. The $3.0-79$ keV broadband X-ray spectral modelling using physically-motivated models, namely MYTORUS, BORUS02 and UXCLUMPY, infers the presence of a torus with a low covering factor of $0.28$, an inclination angle of $77^{\circ}$ $-$ $81^{\circ}$ and Compton-thick line-of-sight column densities ($N_{\rm H,LOS} = 4.13~-~9.26~\times~10^{24}$ cm$^{-2}$) in all the epochs. The joint multi-epoch spectral modelling suggests that the overall structure of the torus is likely to remain unchanged. However, we find tentative evidence for the variable line-of-sight column density on timescales ranging from one day to one week to a few years, suggesting a clumpy circumnuclear material located at sub-parsec to tens of parsec scales.

1.The Detection of a Compact Radio Feature in a Seyfert Galaxy After an Accretion Rate Change

Authors:K. É. Gabányi, K. Smith, S. Frey, Z. Paragi, T. An, A. Moór

Abstract: X-ray binaries are known to show state transitions related to accretion rate changes which are often accompanied with dramatic changes in the jet emission. However, it is not clear whether this characteristics of stellar-mass black hole systems can be scaled up to the accretion disk of active galactic nuclei. The Seyfert 1 galaxy, KUG 1141+371 has been showing a steadily increasing X-ray flux since 2007, and exhibited variability behaviour similar to the state transitions observed in X-ray binaries. It was hypothesised to undergo a rapid boost of mass accretion. If the X-ray binary analogy holds then the appearance of jet emission can also be expected in KUG 1141+371. While the source was not detected in the Faint Images of the Radio Sky at Twenty-centimeters in 1994, it appears in the VLA Sky Survey in 2019 and at 22 GHz in a VLA observation in 2018 at mJy flux density level. Our VLBI observations revealed a compact, flat-spectrum radio feature. Its high brightness temperature indicates the radio emission originates from an AGN.

2.The statistical analysis of the dynamical evolution of the open clusters

Authors:Jayanand Maurya, Y. C. Joshi, Manash Ranjan Samal, Vineet Rawat, Anubha Singh Gour

Abstract: We present the dynamical evolution of ten open clusters which were part of our previous studies. These clusters include both young and intermediate-age open clusters with ages ranging from 25$\pm$19 Myr to 1.78$\pm$0.20 Gyr. The total mass of these clusters ranges from 356.18$\pm$142.90 to 1811.75$\pm$901.03 M$_{\odot}$. The Galactocentric distances to the clusters are in the range of 8.91$\pm$0.02 to 11.74$\pm$0.18 kpc. The study is based on the ground-based UBVRI data supplemented by the astrometric data from the Gaia archive. We studied the minimum spanning tree of the member stars for these clusters. The mass segregation in these clusters was quantified by mass segregation ratios calculated from the mean edge length obtained through the minimum spanning tree. The clusters NGC 2360, NGC 1960, IC 1442, King 21, and SAI 35 have ${\Gamma}_{MSR}$ to be 1.65$\pm$0.18, 1.94$\pm$0.22, 2.21$\pm$0.20, 1.84$\pm$0.23, and 1.96$\pm$0.25, respectively which indicate moderate mass segregation in these clusters. The remaining five clusters are found to exhibit weak or no mass segregation. We used the ratio of half mass radius to the tidal radius i.e. R$_{h}$/R$_{t}$ to investigate the effect of the tidal interactions on the cluster structure and dynamics. The ratios of half mass radii to tidal radii are found to be positively correlated with the Galactocentric distances with a linear slope of 0.06$\pm$0.01 having linear regression coefficient r-square = 0.93 for the clusters.

3.Dust attenuation in galaxies at cosmic dawn from the FirstLight simulations

Authors:Muzammil Mushtaq, Daniel Ceverino, Ralf S. Klessen, Stefan Reissl, Prajwal Hassan Puttasiddappa

Abstract: We study the behaviour of dust in galaxies at cosmic dawn, z=6-8, by coupling the FirstLight simulations with the radiative transfer code POLARIS. The starburst nature of these galaxies and their complex distribution of dust lead to a large diversity of attenuation curves. These follow the Calzetti model only for relatively massive galaxies, Mstars=10^9 Msun. Galaxies with lower masses have steeper curves, consistent with the model for the Small Magellanic Cloud (SMC). The ultraviolet and optical slopes of the attenuation curves are closer to the modified Calzetti model, with a slight preference for the power-law model for galaxies with the highest values of attenuation. We have also examined the relation between the slope in the far-ultraviolet, beta_UV , and the infrared excess, IRX. At z=6, it follows the Calzetti model with a shift to slightly lower beta_UV values due to lower metallicities at lower attenuation. The same relation at z=8 shows a shift to higher IRX values due to a stronger CMB radiation at high-z.

4.Constraining the Molecular Gas Content of Fast Radio Burst (FRB) Host Galaxies

Authors:Jay S. Chittidi, Georgia Stolle-McAllister, Regina A. Jorgenson, Nicolas Tejos, J. Xavier Prochaska, Tarraneh Eftekhari, Wen-fai Fong, Stuart D. Ryder, Ryan M. Shannon

Abstract: We used Bands 6 and 7 of the Atacama Large Millimeter/submillimeter Array (ALMA) in Cycles 7 and 8 to search for $\mathrm{CO}\,(3-2)$ emission from a sample of five fast radio burst (FRB) host galaxies discovered by the Commensal Real-time ASKAP Fast Transients (CRAFT) survey and the Fast and Fortunate for FRB Follow-up (F$^4$) team. These galaxies have redshifts $z \approx 0.16-0.48$, masses log$(M_{\rm star}/M_{\odot})\approx 9.30-10.4$ characteristic of field galaxies, and emission lines indicative of ongoing star formation. We detected three of the five galaxies with luminosities $L'(3-2)\approx0.2-4\times10^8\,\rm K\,km \, s^{-1}\,pc^2$ and set upper limits for the other two. Adopting standard metallicity-dependent CO-to-H$_2$ conversion factors, we estimate molecular gas masses $M_{\rm gas}\approx 0.2-3\times 10^9 \, M_{\odot}$. As a population, FRB host galaxies track the main $M_{\rm star}-M_{\rm gas}$ locus of star-forming galaxies in the present-day universe, with gas fractions of $\mu_{\rm gas}\approx0.1$ and gas depletion times $t_{\rm dep} \gtrapprox 1\,$Gyr. We employ the Kaplan-Meier estimator to compare the redshift-corrected $\mu_{\rm gas}$ and $t_{\rm dep}$ for all known FRB hosts with measurements or upper limits with those from the xCOLD GASS survey and find statistically different gas fractions. The difference is not statistically significant when we consider only the five hosts studied here with consistently determined properties, suggesting more FRB hosts with measured molecular gas masses are needed to robustly study the population. Lastly, we present a multi-wavelength analysis of one host (HG20180924B) combining high-spatial resolution imaging and integral field spectroscopy to demonstrate that future high-resolution observations will allow us to study the host galaxy environments local to the FRBs.

5.Anisotropic Satellite Galaxy Quenching: A Unique Signature of Energetic Feedback by Supermassive Black Holes?

Authors:Juliana S. M. Karp, Johannes U. Lange, Risa H. Wechsler

Abstract: The quenched fraction of satellite galaxies is aligned with the orientation of the halo's central galaxy, such that on average, satellites form stars at a lower rate along the major axis of the central. This effect, called anisotropic satellite galaxy quenching (ASGQ), has been found in observational data and cosmological simulations. Analyzing the IllustrisTNG simulation, Mart\'in-Navarro et al. (2021) recently argued that ASGQ is caused by anisotropic energetic feedback and constitutes "compelling observational evidence for the role of black holes in regulating galaxy evolution." In this letter, we study the causes of ASGQ in state-of-the-art galaxy formation simulations to evaluate this claim. We show that cosmological simulations predict that on average, satellite galaxies along the major axis of the dark matter halo tend to have been accreted at earlier cosmic times and are hosted by subhalos of larger peak halo masses. As a result, a modulation of the quenched fraction with respect to the major axis of the central galaxy is a natural prediction of hierarchical structure formation. We show that ASGQ is predicted by the UniverseMachine galaxy formation model, a model without anisotropic feedback. Furthermore, we demonstrate that even in the IllustrisTNG simulation, anisotropic satellite accretion properties are the main cause of ASGQ. Ultimately, we argue that ASGQ is not a reliable indicator of supermassive black hole feedback in galaxy formation simulations and, thus, should not be interpreted as such in observational data.

6.Fading AGN in Post-Starburst Galaxies

Authors:K. Decker French UIUC, Nicholas Earl UIUC, Annemarie B. Novack UIUC, Bhavya Pardasani UIUC, Vismaya R. Pillai UIUC HKU, Akshat Tripathi UIUC, Margaret E. Verrico UIUC

Abstract: The role of AGN in quenching galaxies and driving the evolution from star-forming to quiescent remains a key question in galaxy evolution. We present evidence from the Mapping Nearby Galaxies at APO (MaNGA) survey for fading AGN activity in 6/93 post-starburst galaxies. These six galaxies show extended emission line regions (EELRs) consistent with ionization from past AGN activity, analogous to "Hanny's voorwerp" and other systems where the OIII5007 emission is bright enough to be visible in broadband imaging. Using the infrared luminosities from IRAS to estimate the current AGN luminosity, we find that 5/6 of the post-starburst galaxies have current AGN which have faded from the peak luminosity required to have ionized the EELRs. Given the rate at which we observe EELRs, the typical EELR visibility timescale, and an estimate of how often EELRs would be visible, we estimate the duty cycle of AGN activity during the post-starburst phase. The timescale for the galaxy to cycle between peaks in AGN luminosity is $t_{\rm EELR}\sim1.1-2.3\times10^5$ yr. Given the rate at which we observe current AGN activity during this phase, we estimate that the AGN spends only 5.3% of this time (or $t_{\rm ON} = 0.6-1.3\times10^4$ yr) in its luminous phase, with the rest of the time spent "off" or in a low-luminosity phase. The length of this duty cycle may explain why so few luminous AGN have been observed during the post-starburst phase, despite evidence for AGN feedback at work.

7.A Mixture of LBG Overdensities in the Fields of Three z between 6 and 7. Quasars: Implications for the Robustness of Photometric Selection

Authors:Jaclyn B. Champagne, Caitlin M. Casey, Steven L. Finkelstein, Micaela Bagley, Olivia R. Cooper, Rebecca L. Larson, Arianna S. Long, Feige Wang

Abstract: The most luminous quasars at $z > 6$ are suspected to be both highly clustered and reside in the most massive dark matter halos in the early Universe, making them prime targets to search for galaxy overdensities and/or protoclusters. We search for Lyman-break dropout-selected galaxies using HST WFC3/ACS broadband imaging in the fields of three $6 < z < 7$ quasars, as well as their simultaneously observed coordinated-parallel fields, and constrain their photometric redshifts using EAZY. One field, J0305-3150, shows a volume density 10$\times$ higher than the blank-field UV luminosity function (UVLF) at M$_{UV} < -20$, with tentative evidence of a 3$\sigma$ overdensity in its parallel field located 15 cMpc away. Another field, J2054-0005, shows an angular overdensity within 500 ckpc from the quasar but still consistent with UVLF predictions within 3$\sigma$, while the last field, J2348-3054, shows no enhancement. We discuss methods for reducing uncertainty in overdensity measurements when using photometric selection and show that we can robustly select LBGs consistent with being physically associated with the quasar, corroborated by existing JWST/NIRCam WFSS data in the J0305 field. Even accounting for incompleteness, the overdensities in J0305 and J2054 are higher for brighter galaxies at short angular separations, suggesting preferential enhancement of more massive galaxies in the immediate vicinity of the quasar. Finally, we compare the LBG population with previously-identified [CII] and mm-continuum companions; the LBG overdensities are not accompanied by an enhanced number of dusty galaxies, suggesting that the overdense quasar fields are not in the bursty star-forming phase sometimes seen in high-redshift protoclusters.

8.WISDOM Project -- XIV. Giant Molecular Clouds in the Central Region of the Barred Spiral Galaxy NGC 5806

Authors:Woorak Choi, Lijie Liu, Martin Bureau, Michele Cappellari, Timothy A. Davis, Jindra Gensior, Fu-Heng Liang, Anan Lu, Thomas G. Williams, Aeree Chung

Abstract: We present high spatial resolution ($\approx24$ pc) Atacama Large Millimeter/sub-millimeter Array $^{12}$CO(2-1) observations of the central region of the nearby barred spiral galaxy NGC 5806. NGC 5806 has a highly structured molecular gas distribution with a clear nucleus, a nuclear ring and offset dust lanes. We identify $170$ spatially- and spectrally-resolved giant molecular clouds (GMCs). These clouds have comparable sizes ($R_{\mathrm{c}}$) and larger gas masses, observed linewidths ($\sigma_{\mathrm{obs,los}}$) and gas mass surface densities than those of clouds in the Milky Way disc. The size -- linewidth relation of the clouds is one of the steepest reported so far ($\sigma_{\mathrm{obs,los}}\propto R_{\mathrm{c}}^{1.20}$), the clouds are on average only marginally bound (with a mean virial parameter $\langle\alpha_{\mathrm{vir}}\rangle\approx2$), and high velocity dispersions are observed in the nuclear ring. These behaviours are likely due to bar-driven gas shocks and inflows along the offset dust lanes, and we infer an inflow velocity of $\approx120$ kms$^{-1}$ and a total molecular gas mass inflow rate of $\approx5$ M$_\odot$ yr$^{-1}$ into the nuclear ring. The observed internal velocity gradients of the clouds are consistent with internal turbulence. The number of clouds in the nuclear ring decreases with azimuthal angle downstream from the dust lanes without clear variation of cloud properties. This is likely due to the estimated short lifetime of the clouds ($\approx6$ Myr), which appears to be mainly regulated by cloud-cloud collision and/or shear processes. Overall, it thus seems that the presence of the large-scale bar and gas inflows to the centre of NGC 5806 affect cloud properties.

9.Compact Steep Spectrum Radio Sources with Enhanced Star Formation are Smaller than $10\,$kpc

Authors:Yjan A. Gordon, Christopher P. O'Dea, Stefi A. Baum, Keith Bechtol, Chetna Duggal, Peter S. Ferguson

Abstract: Compact Steep Spectrum (CSS) radio sources are active galactic nuclei that have radio jets propagating only on galactic scales, defined as having projected linear sizes (LS) of up to $20\,$kpc. CSS sources are generally hosted by massive early-type galaxies with little on-going star formation, however a small fraction are known to have enhanced star formation. Using archival data from the Faint Images of the Radio Sky at Twenty cm survey, the Very Large Array Sky Survey and the Sloan Digital Sky Survey we identify a volume-limited sample of $166$ CSS sources at $z<0.2$ with $L_{1.4\,\text{GHz}}>10^{24}\,\text{W}\,\text{Hz}^{-1}$. Comparing the star formation rates and linear sizes of these CSS sources, we find that the $\approx14\,\%$ of CSS sources with specific star formation rates above $0.01\,\text{Gyr}^{-1}$ all have $\text{LS}<10\,$kpc. We discuss the possible mechanisms driving this result, concluding that it is likely the excess star formation in these sources occurred in multiple bursts and ceased prior to the AGN jet being triggered.

1.Investigation of Stellar Kinematics and Ionized gas Outflows in Local [U]LIRGs

Authors:Ashraf Ayubinia, Yongquan Xue, Huynh Anh Nguyen Le, Fan Zou, Shu Wang, Zhicheng He, Ece Kilerci Eser

Abstract: We explore properties of stellar kinematics and ionized gas in a sample of 1106 local [U]LIRGs from the AKARI telescope. We combine data from $Wide-field\ Infrared\ Survey\ Explorer$ (WISE) and Sloan Digital Sky Survey (SDSS) Data Release 13 (DR13) to fit the spectral energy distribution (SED) of each source to constrain the contribution of AGN to the total IR luminosity and estimate physical parameters such as stellar mass and star-formation rate (SFR). We split our sample into AGNs and weak/non-AGNs. We find that our sample is considerably above the main sequence. The highest SFRs and stellar masses are associated with ULIRGs. We also fit the H$\beta$ and H$\alpha$ regions to characterize the outflows. We find that the incidence of ionized gas outflows in AGN [U]LIRGs ($\sim$ 72\%) is much higher than that in weak/non-AGN ones ($\sim$ 39\%). The AGN ULIRGs have extreme outflow velocities (up to $\sim$ 2300 km s$^{-1}$) and high mass outflow rates (up to $\sim$ 60 \solarm~yr$^{-1}$). Our results suggest that starbursts are insufficient to produce such powerful outflows. We explore the correlations of SFR and specific SFR (sSFR) with ionized gas outflows. We find that AGN hosts with the highest SFRs exhibit a negative correlation between outflow velocity and sSFR. Therefore, in AGNs containing large amounts of gas, the negative feedback scenario might be suggested.

2.Steep Balmer decrement in weak AGNs may be not caused by dust extinction: clues from low-luminosity AGNs and changing-look AGNs

Authors:Jiancheng Wu, Qingwen Wu, Hanrui Xue, Weihua Lei, Bing Lyu

Abstract: The hydrogen Balmer decrement (e.g., $\rm H\alpha/H\beta$) is widely adopted as an indicator of the internal reddening of active galactic nuclei (AGNs). This is challenged by some low-luminosity AGNs (LLAGNs) and changing-look AGNs (CLAGNs), which have steep Balmer decrement but without strong evidence for absorption. We compile a sample of normal AGNs and CLAGNs with a wider distribution of bolometric Eddington ratio ($\lambda_{\rm Edd}=L_{\rm bol}/L_{\rm Edd}$) and find a strong negative correlation between $\rm H\alpha/H\beta$ and $\lambda_{\rm Edd}$, which suggests that the Balmer decrement is also accretion-rate dependent. We further explore the Balmer decrement based on the photoionization model using the Cloudy code by considering spectral energy distribution (SED) from the accretion disk with different accretion rates (e.g., disk/corona and truncated disk at high and low Eddington ratios, respectively). Both the standard disk and truncated disk predict a negative correlation of $\rm H\alpha/H\beta-\lambda_{\rm Edd}$, where the relation is steeper in the case of the truncated disk. The negative correlations are also explored in two single CLAGNs. The measured negative correlation of $\rm H\alpha/H\beta$ -- $\lambda_{\rm Edd}$ is mainly caused by the lower responsivity $({\rm dlog}L_{\rm line}/{\rm dlog}L_{\rm cont})$ in $\rm H\alpha$ relative to that in $\rm H\beta$, due to the larger optical depth in the former. We propose that the steep Balmer decrements in low-Eddington-ratio AGNs (e.g., some Seyferts 1.5-1.9 and CLAGNs) are not simply caused by absorption but mainly caused by the relatively low flux of ionizing photons.

3.Does Feedback from Supermassive Blackhole Co-evolve With Host In Type 2 Quasars?

Authors:S. Jin, J. Wang, M. Z. Kong, R. J. Shen, Y. X. Zhang, X. D. Xu, J. Y. Wei, Z. Xie

Abstract: The feedback from accretion of central supermassive black holes (SMBHs) is a hot topic in the co-evolution of the SMBHs and their host galaxies. By tracing the large scale outflow by the line profile and bulk velocity shift of $[ \rm O~{\scriptsize III}]~ \lambda 5007$, the evolutionary role of outflow is studied here on a large sample of 221 type 2 quasars (QSO2s) extracted from Reyes et al. By following our previous study on local Seyfert 2 galaxies, the current spectral analysis on the SDSS spectroscopic database enables us to arrive at following results: (1) by using the Lick indices, we confirm that QSO2s are on average associated with younger stellar populations than Seyfert galaxies; (2) QSO2s with a stronger outflow are tend to be associated with a younger stellar population, which implies a coevolution between the feedback from SMBH and the host in QSO2s; (3) although an occupation at the high $L_{\rm bol}/L_{\rm Edd}$ end, the QSO2s follow the $L_{\rm bol}/L_{\rm Edd}$-$D_{n}(4000)$ sequence established from local, less-luminous Seyfert galaxies, which suggests a decrease of accretion activity of SMBH and feedback as the circumnuclear stellar population continuously ages.

4.Internal kinematics and structure of the bulge globular cluster NGC 6569

Authors:Cristina Pallanca Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy Istituto Nazionale di Astrofisica, Silvia Leanza Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy Istituto Nazionale di Astrofisica, Francesco R. Ferraro Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy Istituto Nazionale di Astrofisica, Barbara Lanzoni Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy Istituto Nazionale di Astrofisica, Emanuele Dalessandro Istituto Nazionale di Astrofisica, Mario Cadelano Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy Istituto Nazionale di Astrofisica, Enrico Vesperini Department of Astronomy, Indiana University, Bloomington, IN, USA, Livia Origlia Istituto Nazionale di Astrofisica, Alessio Mucciarelli Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy Istituto Nazionale di Astrofisica, Elena Valenti European Southern Observatory, Garching bei Munchen, Germany Excellence Cluster ORIGINS, Garching Bei Munchen, Germany, Andrea Miola Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Ferrara, Italy

Abstract: In the context of a project aimed at characterizing the properties of star clusters in the Galactic bulge, here we present the determination of the internal kinematics and structure of the massive globular cluster NGC 6569. The kinematics has been studied by means of an unprecedented spectroscopic dataset acquired in the context of the ESO-VLT Multi-Instrument Kinematic Survey (MIKiS) of Galactic globular clusters, combining the observations from four different spectrographs. We measured the line-of-sight velocity of a sample of almost 1300 stars distributed between ~0.8" and 770" from the cluster center. From a sub-sample of high-quality measures, we determined the velocity dispersion profile of the system over its entire radial extension (from ~ 5" to ~ 200" from the center), finding the characteristic behavior usually observed in globular clusters, with a constant inner plateau and a declining trend at larger radii. The projected density profile of the cluster has been obtained from resolved star counts, by combining high-resolution photometric data in the center, and the Gaia EDR3 catalog radially extended out to ~20' for a proper sampling of the Galactic field background. The two profiles are properly reproduced by the same King model, from which we estimated updated values of the central velocity dispersion, main structural parameters (such as the King concentration, the core, half-mass, and tidal radii), total mass, and relaxation times. Our analysis also reveals a hint of ordered rotation in an intermediate region of the cluster (40"<r<90", corresponding to $ 2 r_c<r<4.5 r_c$), but additional data are required to properly assess this possibility.

5.Toward a better understanding of the mid-infrared emission in the LMC

Authors:D. Paradis, C. Mény, K. Demyk, A. Noriega-Crespo, I. Ristorcelli

Abstract: In this paper we aim to constrain for the first time the dust emission in the mid-to-far infrared domain, in the LMC, with the use of the Spitzer IRS and MIPS SED data, combined with Herschel data. We also consider UV extinction predictions derived from modeling. We selected 10 regions observed as part of the SAGE-Spec program, to probe dust properties in various environments (diffuse, molecular and ionized regions). All data were smoothed to the 40arcsec angular resolution. The SEDs were modeled with DustEM models, using the standard Mathis RF, as well as three additional RFs, with stellar clusters ages ranging from 4 Myr to 600 Myr. Standard dust models used to reproduce the Galactic diffuse medium are clearly not able to reproduce the dust emission in the MIR wavelength domain. This analysis evidences the need of adjusting parameters describing the dust size distribution and shows a clear distinct behavior according to the type of environments. In addition, whereas the small grain emission always seems to be negligible at long wavelengths in our Galaxy, the contribution of this small dust component could be more important than expected, in the submm-mm range, in the LMC averaged SED. Properties of the small dust component of the LMC are clearly different from those of our Galaxy. Its abundance, significantly enhanced, could be the result of large grains shattering due to strong shocks or turbulence. In addition, this grain component in the LMC systematically shows smaller grain size in the ionized regions compared to the diffuse medium. Predictions of extinction curves show significantly distinct behaviors depending on the dust models but also from one region to another. Comparison of model predictions with the LMC mean extinction curve shows that no model gives satisfactory agreement using the Mathis radiation field while using a harder radiation field tends to improve the agreement

6.Exploring the impact of IMF and binary parameter stochasticity with a binary population synthesis code

Authors:E. R. Stanway Warwick, UK, J. J. Eldridge Auckland, NZ

Abstract: Low mass star formation regions are unlikely to fully populate their initial mass functions, leading to a deficit of massive stars. In binary stellar populations, the full range of binary separations and mass ratios will also be underpopulated. To explore the effects of stochastic sampling in the integrated light of stellar clusters, we calculate models at a broad range of cluster masses, from 10^2 to 10^7 M_sun, using a binary stellar population synthesis code. For clusters with stellar masses less than 10^5 M_sun, observable quantities show substantial scatter and their mean properties reflect the expected deficit of massive stars. In common with previous work, we find that purely stochastic sampling of the initial mass function appears to underestimate the mass of the most massive star in known clusters. However, even with this constraint, the majority of clusters likely inject sufficient kinetic energy to clear their birth clusters of gas. For quantities which directly measure the impact of the most massive stars, such as N_{ion}, xi_{ion} and beta_{UV}, uncertainties due to stochastic sampling dominate over those from the IMF shape or distribution of binary parameters, while stochastic sampling has a negligible effect on the stellar continuum luminosity density.

7.Detection of a Super-Virial Hot Component in the Milky Way Circumgalactic Medium Along Multiple Sight-Lines by Using the Stacking Technique

Authors:Armando Lara-DI, Smita Mathur, Yair Krongold, Sanskriti Das, Anjali Gupta

Abstract: The study of the elusive hot component ($T \gtrsim 10^7$ K) of the Milky Way circumgalactic medium (CGM) is a novel topic to understand Galactic formation and evolution. In this work, we use the stacking technique through 46 lines of sight with Chandra ACIS-S HETG totaling over 10Ms of exposure time and 9 lines of sight with ACIS-S LETG observations totaling over 1Ms of exposure time, to study in absorption the presence of highly ionized metals arising from the super-virial temperature phase of the CGM. Focusing in the spectral range $4 - 8$ $\r{A}$, we were able to confirm the presence of this hot phase with high significance. We detected transitions of Si XIV K$\alpha$ (with total significance of 6.0$\sigma$) and, for the first time, SXVI K (total significance 4.8$\sigma$) in the rest frame of our own Galaxy. For S XVI K$\alpha$ we found a column density of $1.50^{+0.44}_{-0.38} \times 10^{16} \mathrm{cm}^{-2}$. For Si XIV K$\alpha$ we measured a column density of $0.87\pm{0.16} \times 10^{16} \mathrm{cm}^{-2}$. The lines of sight used in this work are spread across the sky, probing widely separated regions of the CGM. Therefore, our results indicate that this newly discovered hot medium extends throughout the halo, and is not related only to the Galactic Bubbles. The hot gas location, distribution, and covering factor, however, remain unknown. This component might contribute significantly to the missing baryons and metals in the Milky Way.

8.FAST-ASKAP Synergy: Quantifying Coexistent Tidal and Ram-Pressure Strippings in the NGC 4636 Group

Authors:Xuchen Lin, Jing Wang, Virginia Kilborn, Eric W. Peng, Luca Cortese, Alessandro Boselli, Ze-Zhong Liang, Bumhyun Lee, Dong Yang, Barbara Catinella, N. Deg, H. Dénes, Ahmed Elagali, P. Kamphuis, B. S. Koribalski, K. Lee-Waddell, Jonghwan Rhee, Li Shao, Kristine Spekkens, Lister Staveley-Smith, T. Westmeier, O. Ivy Wong, Kenji Bekki, Albert Bosma, Min Du, Luis C. Ho, Juan P. Madrid, Lourdes Verdes-Montenegro, Huiyuan Wang, Shun Wang

Abstract: Combining new HI data from a synergetic survey of ASKAP WALLABY and FAST with the ALFALFA data, we study the effect of ram-pressure and tidal interactions in the NGC 4636 group. We develop two parameters to quantify and disentangle these two effects on gas stripping in HI-bearing galaxies: the strength of external forces at the optical-disk edge, and the outside-in extents of HI-disk stripping. We find that gas stripping is widespread in this group, affecting 80% of HI-detected non-merging galaxies, and that 34% are experiencing both types of stripping. Among the galaxies experiencing both effects, the strengths (and extents) of ram-pressure and tidal stripping are independent of each other. Both strengths are correlated with HI-disk shrinkage. The tidal strength is related to a rather uniform reddening of low-mass galaxies ($M_*<10^9\,\text{M}_\odot$) when tidal stripping is the dominating effect. In contrast, ram pressure is not clearly linked to the color-changing patterns of galaxies in the group. Combining these two stripping extents, we estimate the total stripping extent, and put forward an empirical model that can describe the decrease of HI richness as galaxies fall toward the group center. The stripping timescale we derived decreases with distance to the center, from $\mathord{\sim}1\,\text{Gyr}$ around $R_{200}$ to $\mathord{\lesssim}10\,\text{Myr}$ near the center. Gas-depletion happens $\mathord{\sim}3\,\text{Gyr}$ since crossing $2R_{200}$ for HI-rich galaxies, but much quicker for HI-poor ones. Our results quantify in a physically motivated way the details and processes of environmental-effects-driven galaxy evolution, and might assist in analyzing hydrodynamic simulations in an observational way.

9.RadioAstron Space VLBI Imaging of the jet in M87: I. Detection of high brightness temperature at 22 GHz

Authors:Jae-Young Kim, Tuomas Savolainen, Petr Voitsik, Evgeniya V. Kravchenko, Mikhail M. Lisakov, Yuri Y. Kovalev, Hendrik Müller, Andrei P. Lobanov, Kirill V. Sokolovsky, Gabriele Bruni, Philip G. Edwards, Cormac Reynolds, Uwe Bach, Leonid I. Gurvits, Thomas P. Krichbaum, Kazuhiro Hada, Marcello Giroletti, Monica Orienti, James M. Anderson, Sang-Sung Lee, Bong Won Sohn, J. Anton Zensus

Abstract: We present results from the first 22 GHz space very-long-baseline interferometric (VLBI) imaging observations of M87 by RadioAstron. As a part of the Nearby AGN Key Science Program, the source was observed in Feb 2014 at 22 GHz with 21 ground stations, reaching projected $(u,v)$-spacings up to $\sim11\,$G$\lambda$. The imaging experiment was complemented by snapshot RadioAstron data of M87 obtained during 2013--2016 from the AGN Survey Key Science Program. Their longest baselines extend up to $\sim25\,$G$\lambda$. For all these measurements, fringes are detected only up to $\sim$2.8 Earth Diameter or $\sim$3 G$\lambda$ baseline lengths, resulting in a new image with angular resolution of $\sim150\,\mu$as or $\sim20$ Schwarzschild radii spatial resolution. The new image not only shows edge-brightened jet and counterjet structures down to submilliarcsecond scales but also clearly resolves the VLBI core region. While the overall size of the core is comparable to those reported in the literature, the ground-space fringe detection and slightly super-resolved RadioAstron image suggest the presence of substructures in the nucleus, whose minimum brightness temperature exceeds $T_{\rm B, min}\sim10^{12}\,$K. It is challenging to explain the origin of this record-high $T_{\rm B, min}$ value for M87 by pure Doppler boosting effect with a simple conical jet geometry and known jet speed. Therefore, this can be evidence for more extreme Doppler boosting due to a blazar-like small jet viewing angle or highly efficient particle acceleration processes occurring already at the base of the outflow.

10.COMAP Early Science: VIII. A Joint Stacking Analysis with eBOSS Quasars

Authors:Delaney A. Dunne, Kieran A. Cleary, Patrick C. Breysse, Dongwoo T. Chung, Havard T. Ihle, J. Richard Bond, Hans Kristian Eriksen, Joshua Ott Gundersen, Laura C. Keating, Junhan Kim, Jonas Gahr Sturtzel Lunde, Norman Murray, Hamsa Padmanabhan, Liju Philip, Nils-Ole Stutzer, Doga Tolgay, Ingunn Katherine Wehus, Sarah E. Church, Todd Gaier, Andrew I. Harris, Richard Hobbs, James W. Lamb, Charles R. Lawrence, Anthony C. S. Readhead, David P. Woody

Abstract: We present a new upper limit on the cosmic molecular gas density at $z=2.4-3.4$ obtained using the first year of observations from the CO Mapping Array Project (COMAP). COMAP data cubes are stacked on the 3D positions of 282 quasars selected from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) catalog, yielding a 95% upper limit for flux from CO(1-0) line emission of 0.210 Jy km/s. Depending on the assumptions made, this value can be interpreted as either an average CO line luminosity $L'_\mathrm{CO}$ of eBOSS quasars of $\leq 7.30\times10^{10}$ K km pc$^2$ s$^{-1}$, or an average molecular gas density $\rho_\mathrm{H_2}$ in regions of the universe containing a quasar of $\leq 2.02\times10^8$ M$_\odot$ cMpc$^{-3}$. The $L'_\mathrm{CO}$ upper limit falls among CO line luminosities obtained from individually-targeted quasars in the COMAP redshift range, and the $\rho_\mathrm{H_2}$ value is comparable to upper limits obtained from other Line Intensity Mapping (LIM) surveys and their joint analyses. Further, we forecast the values obtainable with the COMAP/eBOSS stack after the full 5-year COMAP Pathfinder survey. We predict that a detection is probable with this method, depending on the CO properties of the quasar sample. Based on these achieved sensitivities, we believe that this technique of stacking LIM data on the positions of traditional galaxy or quasar catalogs is extremely promising, both as a technique for investigating large galaxy catalogs efficiently at high redshift and as a technique for bolstering the sensitivity of LIM experiments, even with a fraction of their total expected survey data.

1.Physical cool-core condensation radius in massive galaxy clusters

Authors:Lei Wang, Paolo Tozzi, Heng Yu, Massimo Gaspari, Stefano Ettori

Abstract: We investigate the properties of cool cores in an optimally selected sample of 37 massive and X-ray-bright galaxy clusters, with regular morphologies, observed with Chandra. We measured the density, temperature, and abundance radial profiles of their intracluster medium (ICM). From these independent quantities, we computed the cooling (tcool) free-fall (tff), and turbulence (teddy) timescales as a function of radius. By requiring the profile-crossing condition, tcool=teddy=1, we measured the cool-core condensation radius Rccc, within which the balancing feeding and feedback processes generate the turbulent condensation rain and related chaotic cold accretion (CCA). We also constrained the complementary (quenched) cooling flow radius Rqcf, obtained via the condition tcool=25Xtff, that encompasses the region of thermally unstable cooling. We find that in our cluster sample and in the limited redshift range considered (1.3E14<M500<16.6E14 Msun, 0.03<z<0.29), the distribution of Rccc peaks at 0.01r500 and the entire range remains below 0.07r500, with a very weak increase with redshift and no dependence on the cluster mass. We find that Rqcf is typically 3 times larger than Rccc, with a wider distribution, and growing more slowly along Rccc, according to an average relation Rqcf~Rccc^(0.46), with a large intrinsic scatter. We suggest that this sublinear relation can be understood as an effect of the micro rain of pockets of cooled gas flickering in the turbulent ICM, whose dynamical and thermodynamical properties are referred to as "macro weather". Substituting the classical cool-core radius R(7.7Gyr), we propose that Rqcf is an indicator of the size of the global cores tied to the long-term macro weather, with the inner Rccc closely tracing the effective condensation rain and chaotic cold accretion (CCA) zone that feeds the central supermassive black hole.

2.Galaxy pairs in The Three Hundred simulations II: studying bound ones and identifying them via machine learning

Authors:Ana Contreras-Santos, Alexander Knebe, Weiguang Cui, Roan Haggar, Frazer Pearce, Meghan Gray, Marco De Petris, Gustavo Yepes

Abstract: Using the data set of The Three Hundred project, i.e. 324 hydrodynamical resimulations of cluster-sized haloes and the regions of radius 15 $h^{-1}$Mpc around them, we study galaxy pairs in high-density environments. By projecting the galaxies' 3D coordinates onto a 2D plane, we apply observational techniques to find galaxy pairs. Based on a previous theoretical study on galaxy groups in the same simulations, we are able to classify the observed pairs into "true" or "false", depending on whether they are gravitationally bound or not. We find that the fraction of true pairs (purity) crucially depends on the specific thresholds used to find the pairs, ranging from around 30 to more than 80 per cent in the most restrictive case. Nevertheless, in these very restrictive cases, we see that the completeness of the sample is low, failing to find a significant number of true pairs. Therefore, we train a machine learning algorithm to help us to identify these true pairs based on the properties of the galaxies that constitute them. With the aid of the machine learning model trained with a set of properties of all the objects, we show that purity and completeness can be boosted significantly using the default observational thresholds. Furthermore, this machine learning model also reveals the properties that are most important when distinguishing true pairs, mainly the size and mass of the galaxies, their spin parameter, gas content and shape of their stellar components.

3.Star formation in the dwarf Seyfert galaxy NGC 4395: Evidence for both AGN and SNe feedback?

Authors:Payel Nandi, C. S. Stalin, D. J. Saikia, S. Muneer, George Mountrichas, Dominika Wylezalek, R. Sagar, Markus Kissler-Patig

Abstract: We present a detailed multi-wavelength study of star formation in the dwarf galaxy NGC 4395 which hosts an active galactic nucleus (AGN). From our observations with the Ultra-Violet Imaging Telescope, we have compiled a catalogue of 284 star forming (SF) regions, out of which we could detect 120 SF regions in H$\alpha$ observations. Across the entire galaxy, we found the extinction corrected star formation rate (SFR) in the far ultra-violet (FUV) to range from 2.0 $\times$ 10$^{-5}$ M$_\odot$yr$^{-1}$ to 1.5 $\times$ 10$^{-2}$ M$_\odot$yr$^{-1}$ with a median of 3.0 $\times$ 10$^{-4}$ M$_\odot$yr$^{-1}$ and age to lie in the range of $\sim$ 1 to 98 Myr with a median of 14 Myr. In H$\alpha$ we found the SFR to range from 7.2 $\times$ 10$^{-6}$ M$_\odot$yr$^{-1}$ to 2.7 $\times$ 10$^{-2}$ M$_\odot$yr$^{-1}$ with a median of 1.7 $\times$ 10$^{-4}$ M$_\odot$yr$^{-1}$ and age to lie between 3 to 6 Myr with a median of 5 Myr. The stellar ages derived from H$\alpha$ show a gradual decline with galactocentric distance. We found three SF regions close to the center of NGC~4395 with high SFR both from H$\alpha$ and UV which could be attributed to feedback effects from the AGN. We also found six other SF regions in one of the spiral arms having higher SFR. These are very close to supernovae remnants which could have enhanced the SFR locally. We obtained a specific SFR (SFR per unit mass) for the whole galaxy 4.64 $\times$ 10$^{-10}$ yr$^{-1}$.

4.Cosmo-tomography toward PKS1830-211: Variability of the quasar and of its foreground molecular absorption monitored with ALMA

Authors:S. Muller Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala, Sweden, I. Marti-Vidal Departament D'Astronomia i Astrofisica, Universitat de Valencia, C. Dr. Moliner 50, E-46100 Burjassot, Valencia, Spain Observatori Astronomic, Universitat de Valencia, C. Catedratico Jose Beltran 2, E-46980 Paterna, Valencia, Spain, F. Combes Observatoire de Paris, LERMA, College de France, CNRS, PSL University, Sorbonne Universite, Paris, France, M. Gerin LERMA, Observatoire de Paris, PSL University, CNRS, Sorbonne Universite, 75014 Paris, France, A. Beelen Aix-Marseille Universite, CNRS CNES, Laboratoire d'Astrophysique de Marseille, 38, Rue Frederic Joliot-Curie, 13388 Marseille, France, C. Horellou Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala, Sweden, M. Guelin Institut de Radioastronomie Millimetrique, 300, rue de la Piscine, 38406 St Martin d'Heres, France, S. Aalto Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala, Sweden, J. H. Black Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala, Sweden, E. van Kampen European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching b. Munchen, Germany

Abstract: Time variability of astronomical sources provides crude information on their typical size and on the implied physical mechanisms. PKS1830-211 is a remarkable radio-bright lensed quasar with a foreground molecular absorber at z=0.89. Small-scale morphological changes in the core-jet structure of the quasar -- which is magnified by the lensing -- result in a varying illumination of the absorber screen, which in turn causes variations in the absorption profile. We aim to study the time variations of the system [...] in order to obtain constraints on both the quasar activity and small-scale structures in the ISM of the absorber. We used ALMA to monitor the submm continuum emission, together with the absorption spectra of the H2O and CH molecules, with 17 visits spread over six months in 2016. [...] From the continuum data, we followed the evolution of the flux density, flux-density ratio, spectral index, and differential polarization between the two lensed images of the quasar; all quantities show significant variations related to the intrinsic activity of the quasar. We propose a simple parametric model of a core plus a ballistic plasmon to account for the continuum evolution, from which we constrain a time delay of 25+/-3~days between lensed images. The spectral lines reveal significant variations in the foreground absorption. A PCA highlights apparent wavy time variations, possibly linked to the helical jet precession period of the quasar. From the deep averaged spectra towards the SW image, we detect the absorption of 13CH and estimate an abundance ratio of 12CH/13CH~150. We also measure the oxygen isotopic ratios, 16O/18O=65.3+/-0.7 and 18O/17O=11.5+/-0.5. Finally, we find a remarkable continuous shallow trough in the water absorption spanning a velocity interval of nearly 500 km/s. This broad absorption could be the signature of an extra-planar molecular component. [Abridged]

5.First constraints of dense molecular gas at z~7.5 from the quasar Pōniuā'ena

Authors:Chiara Feruglio, Umberto Maio, Roberta Tripodi, Jan Martin Winters, Luca Zappacosta, Manuela Bischetti, Francesca Civano, Stefano Carniani, Valentina D'Odorico, Fabrizio Fiore, Simona Gallerani, Michele Ginolfi, Roberto Maiolino, Enrico Piconcelli, Rosa Valiante, Maria Vittoria Zanchettin

Abstract: We report the detection of CO(6-5) and CO(7-6) and their underlying continua from the host galaxy of quasar J100758.264+211529.207 (P\=oniu\=a'ena) at z=7.5419, obtained with the NOrthern Extended Millimeter Array (NOEMA). P\=oniu\=a'ena belongs to the HYPerluminous quasars at the Epoch of ReionizatION (HYPERION) sample of 17 $z>6$ quasars selected to be powered by supermassive black holes (SMBH) which experienced the fastest mass growth in the first Gyr of the Universe. The one reported here is the highest-redshift measurement of the cold and dense molecular gas to date. The host galaxy is unresolved and the line luminosity implies a molecular reservoir of $\rm M(H_2)=(2.2\pm0.2)\times 10^{10}$ $\rm M_\odot$, assuming a CO spectral line energy distribution typical of high-redshift quasars and a conversion factor $\alpha=0.8$ $\rm M_{\odot} (K\,km \, s^{-1} \,pc^{2})^{-1} $. We model the cold dust spectral energy distribution (SED) to derive a dust mass of M$_{\rm dust} =(2.1\pm 0.7)\times 10^8$ $\rm M_\odot$, and thus a gas to dust ratio $\sim100$. Both the gas and dust mass are not dissimilar from the reservoir found for luminous quasars at $z\sim6$. We use the CO detection to derive an estimate of the cosmic mass density of $\rm H_2$, $\Omega_{H_2} \simeq 1.31 \times 10^{-5}$. This value is in line with the general trend suggested by literature estimates at $ z < 7 $ and agrees fairly well with the latest theoretical expectations of non-equilibrium molecular-chemistry cosmological simulations of cold gas at early times.

6.The effect of the LMC on the Milky Way system

Authors:Eugene Vasiliev

Abstract: We review the recent theoretical and observational developments concerning the interaction of the Large Magellanic Cloud (LMC) with the Milky Way and its neighbourhood. An emerging picture is that the LMC is a fairly massive companion (10-20% of the Milky Way mass) and just passed the pericentre of its orbit, likely for the first time. The gravitational perturbation caused by the LMC is manifested at different levels. The most immediate effect is the deflection of orbits of stars, stellar streams or satellite galaxies passing in the vicinity of the LMC. Less well known but equally important is the displacement (reflex motion) of central regions of the Milky Way about the centre of mass of both galaxies. Since the Milky Way is not a rigid body, this displacement varies with the distance from the LMC, and as a result, the Galaxy is deformed and its outer regions (beyond a few tens kpc) acquire a net velocity with respect to its centre. These phenomena need to be taken into account at the level of precision warranted by current and future observational data, and improvements on the modelling side are also necessary for an adequate interpretation of these data.

7.The role of mass and environment in the build up of the quenched galaxy population since cosmic noon

Authors:E. Taylor, O. Almaini, M. Merrifield, D. Maltby, V. Wild, W. G. Hartley, K. Rowlands

Abstract: We conduct the first study of how the relative quenching probability of galaxies depends on environment over the redshift range $0.5 < z < 3$, using data from the UKIDSS Ultra-Deep Survey. By constructing the stellar mass functions for quiescent and post-starburst (PSB) galaxies in high, medium and low density environments to $z = 3$, we find an excess of quenched galaxies in dense environments out to at least $z \sim 2$. Using the growth rate in the number of quenched galaxies, combined with the star-forming galaxy mass function, we calculate the probability that a given star-forming galaxy is quenched per unit time. We find a significantly higher quenching rate in dense environments (at a given stellar mass) at all redshifts. Massive galaxies (M$_* > 10^{10.7}$ M$_{\odot}$) are on average 1.7 $\pm$ 0.2 times more likely to quench per Gyr in the densest third of environments compared to the sparsest third. Finally, we compare the quiescent galaxy growth rate to the rate at which galaxies pass through a PSB phase. Assuming a visibility timescale of 500 Myr, we find that the PSB route can explain $\sim$ 50\% of the growth in the quiescent population at high stellar mass (M$_* > 10^{10.7}$ M$_{\odot}$) in the redshift range $0.5 < z < 3$, and potentially all of the growth at lower stellar masses.

1.Mock X-ray observations of hot gas with L-Galaxies semi-analytic models of galaxy formation

Authors:Wenxin Zhong, Jian Fu, Shen Shiyin, Yuan Feng

Abstract: We create mock X-ray observations of hot gas in galaxy clusters with a new extension of L-Galaxies semi-analytic model of galaxy formation, which includes the radial distribution of hot gas in each halo. Based on the model outputs, we first build some mock light cones, then generate mock spectra with SOXS package and derive the mock images in the light cones. Using the mock data, we simulate the mock X-ray spectra for ROSAT all-sky survey, and compare the mock spectra with the observational results. Then, we consider the design parameters of HUBS mission and simulate the observation of the halo hot gas for HUBS as an important application of our mock work. We find: (1) Our mock data match the observations by current X-ray telescopes. (2) The survey of hot baryons in resolved clusters by HUBS is effective below redshift 0.5, and the observations of the emission lines in point-like sources at z>0.5 by HUBS help us understand the hot baryons in the early universe. (3) By taking the advantage of the large simulation box and flexibility in semi-analytic models, our mock X-ray observations provide the opportunity to make target selection and observation strategies for forthcoming X-ray facilities.

2.Far-infrared line emission from the outer Galaxy cluster Gy 3-7 with SOFIA/FIFI-LS: Physical conditions and UV fields

Authors:N. Le, A. Karska, M. Figueira, M. Sewiło, A. Mirocha, Ch. Fischer, M. Kaźmierczak-Barthel, R. Klein, M. Gawroński, M. Koprowski, K. Kowalczyk, W. J. Fischer, K. M. Menten, F. Wyrowski, C. König, L. E. Kristensen

Abstract: (abridged) Far-infrared (FIR) line emission provides key information about the gas cooling and heating due to shocks and UV radiation associated with the early stages of star formation. Gas cooling via FIR lines might, however, depend on metallicity. We aim to quantify the FIR line emission and determine the spatial distribution of the CO rotational temperature, ultraviolet (UV) radiation field, and H2 number density toward the embedded cluster Gy 3-7 in the CMa-l224 star-forming region, whose metallicity is expected to be intermediate between that of the LMC and the Solar neighborhood. By comparing the total luminosities of CO and [O I] toward Gy 3-7 with values found for low- and high-mass protostars extending over a broad range of metallicities, we also aim to identify the possible effects of metallicity on the FIR line cooling within our Galaxy. We studied SOFIA/FIFI-LS spectra of Gy 3-7 covering several FIR lines. The spatial extent of CO high-J (J>14) emission resembles that of the elongated 160 um continuum emission detected with Herschel. The CO transitions from J=14-13 to J=16-15 are detected throughout the cluster and show a median rotational temperature of 170+/-30 K on Boltzmann diagrams. Comparisons to other protostars observed with Herschel show a good agreement with intermediate-mass sources in the inner Galaxy. Assuming an origin of the [O I] and high-J CO emission in UV-irradiated C-shocks, we obtained pre-shock H2 number densities of 10^4-5 cm-3 and UV radiation field strengths of 0.1-10 Habing fields. Far-IR line observations reveal ongoing star formation in Gy 3-7, dominated by intermediate-mass Class 0/I young stellar objects. The ratio of molecular-to-atomic far-IR line emission shows a decreasing trend with bolometric luminosities of the protostars. However, it does not indicate that the low-metallicity has an impact on the line cooling in Gy 3-7.

3.On the hosts of neutron star mergers in the nearby Universe

Authors:L. Cavallo, L. Greggio

Abstract: Recently, the characterisation of binary systems of neutron stars has become central in various fields such as gravitational waves, gamma-ray bursts (GRBs), and the chemical evolution of galaxies. In this work, we explore possible observational proxies that can be used to infer some characteristics of the delay time distribution (DTD) of neutron star mergers (NSMs). We construct a sample of model galaxies that fulfils the observed galaxy stellar mass function, star formation rate versus mass relation, and the cosmic star formation rate density. The star formation history of galaxies is described with a log-normal function characterised by two parameters: the position of the maximum and the width of the distribution. We assume a theoretical DTD that mainly depends on the lower limit and the slope of the distribution of the separations of the binary neutron stars systems at birth. We find that the current rate of NSMs ($\mathcal{R}=320^{+490}_{-240}$ Gpc$^{-3}$yr$^{-1}$) requires that $\sim0.3$ per cent of neutron star progenitors lives in binary systems with the right characteristics to lead to a NSM within a Hubble time. We explore the expected relations between the rate of NSMs and the properties of the host galaxy. We find that the most effective proxy for the shape of the DTD of NSMs is the current star formation activity of the typical host. At present, the fraction of short-GRBs observed in star-forming galaxies favours DTDs with at least $\sim40\%$ of mergers within $100$ Myr. This conclusion will be put on a stronger basis with larger samples of short-GRBs with host association (e.g. $600$ events at $z \leq 1$)

4.Empirical measurement of the dynamical ages of three globular clusters and some considerations on the use of the dynamical clock

Authors:Francesco R. Ferraro, Barbara Lanzoni, Enrico Vesperini, Mario Cadelano, Dan Deras, Cristina Pallanca

Abstract: We have used the ``dynamical clock'' to measure the level of dynamical evolution reached by three Galactic globular clusters (namely, NGC 3201, NGC 6316 and NGC 6440). This is an empirical method that quantifies the level of central segregation of blue stragglers stars (BSSs) within the cluster half-mass radius by means of the $A^+_{rh}$ parameter, defined as the area enclosed between the cumulative radial distribution of BSSs and that of a lighter population. The total sample with homogeneous determinations of $A^+_{rh}$ now counts a gran-total of 59 clusters: 52 old GCs in the Milky Way (including the three investigated here), 5 old clusters in the Large Magellanic Cloud, and 2 young systems in the Small Magellanic Cloud. The three objects studied here nicely nest into the correlation between $A^+_{rh}$ and the central relaxation time defined by the previous sample, thus proving and consolidating the use of the dynamical clock as an excellent tracer of the stage of star cluster dynamical evolution in different galactic environments. Finally, we discuss the advantages of using the dynamical clock as an indicator of star cluster dynamical ages, compared to the present-day central relaxation time.

5.Outflows in the Gaseous Discs of Active Galaxies and their impact on Black Hole Scaling Relations

Authors:N. Menci, F. Fiore, F. Shankar, L. Zanisi, C. Feruglio

Abstract: To tackle the still unsolved and fundamental problem of the role of Active Galactic Nuclei (AGN) feedback in shaping galaxies, in this work we implement a new physical treatment of AGN-driven winds into our semi-analytic model of galaxy formation. To each galaxy in our model, we associate solutions for the outflow expansion and the mass outflow rates in different directions, depending on the AGN luminosity, on the circular velocity of the host halo, and on gas content of the considered galaxy. To each galaxy we also assign an effective radius derived from energy conservation during merger events, and a stellar velocity dispersion self-consistently computed via Jeans modelling. We derive all the main scaling relations between Black hole (BH) mass and total/bulge stellar mass, velocity dispersion, host halo dark matter mass, and star formation efficiency. We find that our improved AGN feedback mostly controls the dispersion around the relations but plays a subdominant role in shaping slopes and/or normalizations of the scaling relations. Including possible limited-resolution selection biases in the model provides better agreement with the available data. The model does not point to any more fundamental galactic property linked to BH mass, with velocity dispersion playing a similar role with respect to stellar mass, in tension with present data. In line with other independent studies carried out on comprehensive semi-analytic and hydrodynamic galaxy-BH evolution models, our current results signal either an inadequacy of present cosmological models of galaxy formation in fully reproducing the local scaling relations, in terms of both shape and residuals, and/or point to an incompleteness issue affecting the local sample of dynamically-measured BHs.

6.Spectroscopic age estimates for 180 000 APOGEE red-giant stars: Precise spatial and kinematic trends with age in the Galactic disc

Authors:F. Anders, P. Gispert, B. Ratcliffe, C. Chiappini, I. Minchev, S. Nepal, A. B. A. Queiroz, J. A. S. Amarante, T. Antoja, G. Casali, L. Casamiquela, A. Khalatyan, A. Miglio, H. Perottoni, M. Schultheis

Abstract: Over the last few years, many studies have found an empirical relationship between the abundance of a star and its age. Here we estimate spectroscopic stellar ages for 178 825 red-giant stars observed by the APOGEE survey with a median statistical uncertainty of 17%. To this end, we use the supervised machine learning technique XGBoost, trained on a high-quality dataset of 3 060 red-giant and red-clump stars with asteroseismic ages observed by both APOGEE and Kepler. After verifying the obtained age estimates with independent catalogues, we investigate some of the classical chemical, positional, and kinematic relationships of the stars as a function of their age. We find a very clear imprint of the outer-disc flare in the age maps and confirm the recently found split in the local age-metallicity relation. We present new and precise measurements of the Galactic radial metallicity gradient in small age bins between 0.5 and 12 Gyr, confirming a steeper metallicity gradient for 2-5 Gyr old populations and a subsequent flattening for older populations mostly produced by radial migration. In addition, we analyse the dispersion about the abundance gradient as a function of age. We find a clear power-law trend (with an exponent $\beta\approx0.15$) for this relation, indicating a smooth radial migration history in the Galactic disc over the past 7-9 Gyr. Departures from this power law are detected at ages of 8 Gyr (possibly related to the Gaia Sausage/Enceladus merger) and 2.75 Gyr (possibly related to an enhancement of the star-formation rate in the Galactic disc). Finally, we confirm previous measurements showing a steepening in the age-velocity dispersion relation at around 9 Gyr, but now extending it over a large extent of the Galactic disc (5 kpc < RGal < 13 kpc). [Abridged]

7.Discovery of Five Green Pea Galaxies with Double-peaked Narrow [OIII] Lines

Authors:Ruqiu Lin, Zhen-Ya Zheng, Jun-Xian Wang, Fang-Ting Yuan, James E. Rhoads, Sangeeta Malhotra, Tao An, Chunyan Jiang, Shuairu Zhu, Rahna P. T., Xiang Ji, Mainak Singha

Abstract: Although double-peaked narrow emission-line galaxies have been studied extensively in the past years, only a few are reported with the green pea galaxies (GPs). Here we present our discovery of five GPs with double-peaked narrow [OIII] emission lines, referred to as DPGPs, selected from the LAMOST and SDSS spectroscopic surveys. We find that these five DPGPs have blueshifted narrow components more prominent than the redshifted components, with velocity offsets of [OIII]$\lambda$5007 lines ranging from 306 to 518 $\rm km\, s^{-1}$ and full widths at half maximums (FWHMs) of individual components ranging from 263 to 441 $\rm km\, s^{-1}$. By analyzing the spectra and the spectral energy distributions (SEDs), we find that they have larger metallicities and stellar masses compared with other GPs. The H$\alpha$ line width, emission-line diagnostic, mid-infrared color, radio emission, and SED fitting provide evidence of the AGN activities in these DPGPs. They have the same spectral properties of Type 2 quasars. Furthermore, we discuss the possible nature of the double-peaked narrow emission-line profiles of these DPGPs and find that they are more likely to be dual AGN. These DPGP galaxies are ideal laboratories for exploring the growth mode of AGN in the extremely luminous emission-line galaxies, the co-evolution between AGN and host galaxies, and the evolution of high-redshift galaxies in the early Universe.

8.Saying Hallo to M94's Stellar Halo: Investigating the Accretion History of the Largest Pseudobulge Host in the Local Universe

Authors:Katya Gozman, Eric F. Bell, Adam Smercina, Paul Price, Jeremy Bailin, Roelof S. de Jong, Richard D'Souza, In Sung Jang, Antonela Monachesi, Colin Slater

Abstract: It is not yet settled how the combination of secular processes and merging gives rise to the bulges and pseudobulges of galaxies. The nearby ($D\sim$ 4.2 Mpc) disk galaxy M94 (NGC 4736) has the largest pseudobulge in the local universe, and offers a unique opportunity for investigating the role of merging in the formation of its pseudobulge. We present a first ever look at M94's stellar halo, which we expect to contain a fossil record of M94's past mergers. Using Subaru's Hyper Suprime-Cam, we resolve and identify red giant branch (RGB) stars in M94's halo, finding two distinct populations. After correcting for completeness through artificial star tests, we can measure the radial profile of each RGB population. The metal-rich RGB stars show an unbroken exponential profile to a radius of 30 kpc that is a clear continuation of M94's outer disk. M94's metal poor stellar halo is detectable over a wider area and clearly separates from its metal-rich disk. By integrating the halo density profile, we infer a total accreted stellar mass of $\sim 2.8 \times 10^8 M_\odot$, with a median metallicity of [M/H] $=-$1.4. This indicates that M94's most-massive past merger was with a galaxy similar to, or less massive than, the Small Magellanic Cloud. Few nearby galaxies have had such a low-mass dominant merger; therefore we suggest that M94's pseudobulge was not significantly impacted by merging.

1.The power spectrum of extended [C II] halos around high redshift galaxies

Authors:Meng Zhang, Andrea Ferrara, Bin Yue

Abstract: ALMA observations have detected extended ($\simeq 10$ kpc) [C II] halos around high-redshift ($z \gtrsim 5$) star-forming galaxies. If such extended structures are common, they may have an impact on the line intensity mapping (LIM) signal. We compute the LIM power spectrum including both the central galaxy and the [C II] halo, and study the detectability of such signal in an ALMA LIM survey. We model the central galaxy and the [C II] halo brightness with a S\'ersic+exponential profile. The model has two free parameters: the effective radius ratio $f_{R_e}$, and the central surface brightness ratio, $f_{\Sigma}$, between the two components. [C II] halos can significantly boost the LIM power spectrum signal. For example, for relatively compact [C II] halos ($f_\Sigma=0.4$, $f_{R_{\rm e}}=2.0$), the signal is boosted by $\simeq 20$ times; for more extended and diffuse halos ($f_\Sigma=0.1, f_{R_{\rm e}}=6.0$), the signal is boosted by $\simeq 100$ times. For the ALMA ASPECS survey (resolution $\theta_{\rm beam} = 1.13''$, survey area $\Omega_{\rm survey}=2.9\,\rm arcmin^{2}$), the [C II] power spectrum is detectable only if the deL14d [C II] - SFR relation holds. However, with an optimized survey ($\theta_{\rm beam} = 0.232''$, $\Omega_{\rm survey}=2.0\,\rm deg^{2}$), the power spectrum is detectable for almost all the [C II] - SFR relations considered in this paper. Such a survey can constrain $f_\Sigma$ ($f_{R_{\rm e}}$) with a relative uncertainty of $60\%$ ($20\%$). A successful LIM experiment will provide unique constraints on the nature, origin, and frequency of extended [C II] halos, and the [C II] - SFR relation at early times.

2.Radio Galaxy Zoo EMU: Towards a Semantic Radio Galaxy Morphology Taxonomy

Authors:Micah Bowles, Hongming Tang, Eleni Vardoulaki, Emma L. Alexander, Yan Luo, Lawrence Rudnick, Mike Walmsley, Fiona Porter, Anna M. M. Scaife, Inigo Val Slijepcevic, Elizabeth A. K. Adams, Alexander Drabent, Thomas Dugdale, Gülay Gürkan, Andrew M. Hopkins, Eric F. Jimenez-Andrade, Denis A. Leahy, Ray P. Norris, Syed Faisal ur Rahman, Xichang Ouyang, Gary Segal, Stanislav S. Shabala, O. Ivy Wong

Abstract: We present a novel natural language processing (NLP) approach to deriving plain English descriptors for science cases otherwise restricted by obfuscating technical terminology. We address the limitations of common radio galaxy morphology classifications by applying this approach. We experimentally derive a set of semantic tags for the Radio Galaxy Zoo EMU (Evolutionary Map of the Universe) project and the wider astronomical community. We collect 8,486 plain English annotations of radio galaxy morphology, from which we derive a taxonomy of tags. The tags are plain English. The result is an extensible framework which is more flexible, more easily communicated, and more sensitive to rare feature combinations which are indescribable using the current framework of radio astronomy classifications.

3.Late-formed halos prefer to host quiescent central galaxies. I. Observational results

Authors:Kai Wang, Yangyao Chen, Qingyang Li, Xiaohu Yang

Abstract: The star formation and quenching of central galaxies are regulated by the assembly histories of their host halos. In this work, we use the central stellar mass to halo mass ratio as a proxy of halo formation time, and we devise three different models, from the physical hydrodynamical simulation to the empirical statistical model, to demonstrate its robustness. With this proxy, we inferred the dependence of the central galaxy properties on the formation time of their host halos using the SDSS main galaxy sample, where central galaxies are identified with the halo-based group finder. We found that central galaxies living in late-formed halos have higher quiescent fractions and lower spiral fractions than their early-formed counterparts by $\lesssim$ 8%. Finally, we demonstrate that the group finding algorithm has a negligible impact on our results.

4.Galaxy clusters in the Vela supercluster. -- I. Deep NIR catalogues

Authors:N. Hatamkhani, R. C. Kraan-Korteweg, S. L. Blyth, K. Said, A. Elagali

Abstract: We present six deep Near-InfraRed (JHK_s) photometric catalogues of galaxies identified in six cluster candidates (VC02, VC04, VC05, VC08, VC10, VC11) within the Vela Supercluster (VSCL) as part of our efforts to learn more about this large supercluster which extends across the zone of avoidance (l=272.5 \pm 20 deg, b= \pm 10 deg, at cz~ 18000 km/s). The observations were conducted with the InfraRed Survey Facility (IRSF), a 1.4m telescope situated at the South African Astronomical Observatory (SAAO) in Sutherland. The images in each cluster cover ~ 80% of their respective Abell radii. We identified a total number of 1715 galaxies distributed over the six cluster candidates, of which only ~ 15% were previously known. We study the structures and richnesses of the six clusters out to the cluster-centric completeness radius of r_c<1.5 Mpc and magnitude completeness limit of K_s^0<15.5 mag, using their iso-density contour maps and radial density profiles. The analysis shows VC04 to be the richest of the six. It is a massive cluster comparable to the Coma and Norma clusters, although its velocity dispersion, sigma=455 km/s, seems rather low for a rich cluster. VC02 and VC05 are found to be relatively rich clusters while VC08 is rather poor. Also, VC05 has the highest central number density among the six. VC11 is an intermediate cluster that contains two major subclusters while VC10 has a filament-like structure and is likely not to be a cluster after all.

5.Physical and chemical complexity in high-mass star-forming regions with ALMA. I. Overview and evolutionary trends of physical properties

Authors:Caroline Gieser, Henrik Beuther, Dmitry Semenov, Aida Ahmadi, Thomas Henning, Molly Wells

Abstract: In this study, we investigate how physical properties, such as the density and temperature profiles, evolve on core scales through the evolutionary sequence during high-mass star formation ranging from protostars in cold infrared dark clouds to evolved UCHII regions. We observed 11 high-mass star-forming regions with ALMA at 3 mm wavelengths. Based on the 3 mm continuum morphology and recombination line emission, tracing locations with free-free (ff) emission, the fragmented cores analyzed in this study are classified into either dust or dust+ff cores. In addition, we resolve three cometary UCHII regions with extended 3 mm emission that is dominated by free-free emission. The temperature structure and radial profiles (T~r^-q ) are determined by modeling molecular emission of CH3CN and CH313CN with XCLASS and by using the HCN-to- HNC intensity ratio as probes for the gas kinetic temperature. The density profiles (n~r^-p ) are estimated from the 3 mm continuum visibility profiles. The masses M and H2 column densities N(H2) are then calculated from the 3 mm dust continuum emission. Results. We find a large spread in mass and peak H2 column density in the detected sources ranging from 0.1-150 Msun and 10^23 - 10^26 cm-2 , respectively. Including the results of the CORE and CORE-extension studies (Gieser et al. 2021, 2022) to increase the sample size, we find evolutionary trends on core scales for the temperature power-~law index q increasing from 0.1 to 0.7 from infrared dark clouds to UCHII regions, while for the the density power-law index p on core scales, we do not find strong evidence for an evolutionary trend. However, we find that on the larger clump scales throughout these evolutionary phases the density profile flattens from p = 2.2 to p = 1.2. (abridged)

6.UVIT view of NGC 5291: Ongoing star formation in tidal dwarf galaxies at ~ 0.35 kpc resolution

Authors:Rakhi R, Geethika Santhosh, Prajwel Joseph, Koshy George, Smitha Subramanian, Indulekha Kavila, J. Postma, Pierre-Alain Duc, Patrick Côté, Luca Cortese, S. K. Ghosh, Annapurni Subramaniam, Shyam Tandon, John Hutchings, P Samuel Wesley, Aditya Bharadwaj, Neeran Niroula

Abstract: NGC 5291, an early-type galaxy surrounded by a giant HI ring, is believed to be formed from collision with another galaxy. Several star forming complexes and tidal dwarf galaxies are distributed along the collisional ring which are sites of star formation in environments where extreme dynamical effects are involved. Dynamical effects can affect the star formation properties and the spatial distribution of star forming complexes along the tidal features. To study and quantify the star formation activity in the main body and in the ring structure of the NGC 5291 system, we use high spatial resolution FUV and NUV imaging observations from the Ultraviolet Imaging Telescope onboard AstroSat. A total of 57 star-forming knots are identified to be part of this interacting system out of which 12 are new detections (star forming complexes that lie inside the HI contour) compared to the previous measurements from lower resolution UV imaging. We estimate the attenuation in UV for each of the resolved star-forming knots using the UV spectral slope $\beta$, derived from the FUV-NUV colour. Using the extinction corrected UV fluxes, we derive the star formation rate of the resolved star forming complexes. The extinction corrected total star formation rate of this system is estimated as 1.75 $\pm$ 0.04 $M_{\odot}/yr$. The comparison with dwarf galaxy populations (BCD, Sm and dIm galaxies) in the nearby Universe shows that many of the knots in the NGC 5291 system have SFR values comparable to the SFR of BCD galaxies.

7.The distance to the Serpens South Cluster from H2O masers

Authors:Gisela N. Ortiz-Leon, Sergio A. Dzib, Laurent Loinard, Yan Gong, Thushara Pillai Adele Plunkett

Abstract: In this Letter, we report Very Long Baseline Array observations of 22 GHz water masers toward the protostar CARMA-6, located at the center of the Serpens South young cluster. From the astrometric fits to maser spots, we derive a distance of 440.7+/-3.5 pc for the protostar (1% error). This represents the best direct distance determination obtained so far for an object this young and deeply embedded in this highly obscured region. Taking into account depth effects, we obtain a distance to the cluster of 440.7+/-4.6 pc. Stars visible in the optical that have astrometric solutions in the Gaia Data Release 3 are, on the other hand, all located in the periphery of the cluster. Their mean distance of 437 (+51, -41) pc is consistent within 1-sigma with the value derived from maser astrometry. As the maser source is just at the center of Serpens South, we finally solve the ambiguity of the distance to this region that has prevailed over the years.

8.The linear response of stellar systems does not diverge at marginal stability

Authors:Chris Hamilton IAS, Tobias Heinemann NBI

Abstract: The linear response of a stellar system's gravitational potential to a perturbing mass comprises two distinct contributions. Most famously, the system will respond by forming a polarization `wake' around the perturber. At the same time, the perturber may also excite one or more `normal modes', i.e. coherent oscillations of the entire stellar system which are either stable or unstable depending on the system parameters. The amplitude of the first (wake) contribution is known to diverge as a system approaches marginal stability. In this paper we consider the linear response of a homogeneous stellar system to a point mass moving on a straight line orbit. We prove analytically that the divergence of the wake response is in fact cancelled by a corresponding divergence in the normal mode response, rendering the total response finite. We demonstrate this cancellation explicitly for a box of stars with Maxwellian velocity distribution. Our results imply that polarization wakes may be much less efficient drivers of secular evolution than previously thought. More generally, any prior calculation that accounted for wakes but ignored modes may need to be revised.

1.HI 21 cm Extended Structures to the North-East, and South-West of NGC 5595: VLA Observations of the Disk Galaxy Pair NGC 5595 and NGC 5597

Authors:J. Antonio Garcia-Barreto UNAM, Emmanuel Momjian NRAO

Abstract: We report VLA B-configuration observations of the HI 21 cm line on the close disk galaxy pair NGC 5595 and NGC 5597. At the angular resolution of the observations, $\sim7.1'' \times 4.2''$, while most of the HI 21 cm in NGC 5595 and in NGC 5597 has the same extent as the optical disk, we have detected for the first time extended structures (streamers) to the north-east (NE), and south-west (SW) of NGC 5595 with no counterparts in blue, red optical (continuum), 20 cm radio continuum, or H$\alpha$ spectral-line emission. One structure is extended by $\sim 45''$ to the NE with blue-shifted velocities, and the other by $\sim 20''$ to the SW with red-shifted velocities with respect to the systemic velocity. No HI 21 cm emission is detected from the innermost central (nuclear) regions of either galaxy. Lower angular resolution HI 21 cm imaging indicates the non-existence of any intergalactic HI 21 cm gas as tails or bridges between the two galaxies. Our new 20 cm radio continuum emission image of NGC 5597 shows a strong unresolved elongated structure at the central region, in the north-east south-west direction, very similar to the spatial location of the innermost H$\alpha$ spectral line emission. There is no 20 cm continuum emission from its north spiral arm. In NGC 5595, the 20 cm radio continuum image shows no continuum emission from the NE nor the SW extended structures with HI 21 cm emission.

2.Far-infrared Polarization of the Supernova Remnant Cassiopeia A with SOFIA HAWC+

Authors:Jeonghee Rho SETI, Aravind P. Ravi UTA, Le Ngoc Tram MPIRA, Thiem Hoang KASI, Jérémy Chastenet Ghent U, Matthew Millard UTA & UIowa, Michael J. Barlow UCL, Ilse De Looze Ghent U, Haley L. Gomez Cardiff, Florian Kirchschlager Ghent U & UCL, Loretta Dunne Cardiff

Abstract: We present polarization observations of the young supernova remnant (SNR) Cas A using the High-resolution Airborne Wideband Camera-Plus (HAWC+) instrument onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA). The polarization map at 154 microns reveals dust grains with strong polarization fractions (5 - 30 percent), supporting previous measurements made over a smaller region of the remnant at 850 microns. The 154 microns emission and the polarization signal is coincident with a region of cold dust observed in the southeastern shell and in the unshocked central ejecta. The highly polarized far-IR emission implies the grains are large (greater than 0.14 microns) and silicate-dominated. The polarization level varies across the SNR, with an inverse correlation between the polarization degree and the intensity and smaller polarization angle dispersion for brighter SNR emission. Stronger polarization is detected between the bright structures. This may result from a higher collision rate between the gas and dust producing a lower grain alignment efficiency where the gas density is higher. We use the dust emission to provide an estimate of the magnetic field strength in Cas A using the Davis-Chandrasekhar-Fermi method. The high polarization level is direct evidence that grains are highly elongated and strongly aligned with the magnetic field of the SNR. The dust mass from the polarized region is 0.14+-0.04 Msun, a lower limit of the amount of dust present within the ejecta of Cas A. This result strengthens the hypothesis that core-collapse SNe are an important contributor to the dust mass in high redshift galaxies.

3.Fermionic Dark Matter: Physics, Astrophysics, and Cosmology

Authors:C. R. Arguüelles, E. A. Becerra-Vergara, J. A. Rueda, R. Ruffini

Abstract: The nature of dark matter (DM) is one of the most relevant questions in modern astrophysics. We present a brief overview of recent results that inquire into a possible fermionic quantum nature of the DM particles, focusing mainly on the interconnection between the microphysics of the neutral fermions {and the macrophysical structure of galactic halos, including their formation both in the linear and non-linear cosmological regimes. We discuss the general relativistic Ruffini-Arg\"uelles-Rueda (RAR) model of fermionic DM in galaxies, its applications to the Milky Way, the possibility that the Galactic center harbors a DM core instead of a supermassive black hole (SMBH), the S-cluster stellar orbits with an in-depth analysis of the S2's orbit including precession, the application of the RAR model to other galaxy types (dwarf, elliptic, big elliptic and galaxy clusters), and universal galaxy relations. All the above focusing on the model parameters constraints, most relevant to the fermion mass. We also connect the RAR model fermions with particle physics DM candidates, self-interactions, and galactic observables constraints. The formation and stability of core-halo galactic structures predicted by the RAR model and their relation to warm DM cosmologies are also treated. Finally, we briefly discuss how gravitational lensing, dynamical friction, and the formation of SMBHs can also probe the DM nature.

4.Direct observations of the atomic-molecular phase transition in the Milky Way's nuclear wind

Authors:Karlie A. Noon, Mark R. Krumholz, Enrico M. Di Teodoro, Naomi M. McClure-Griffiths, Felix J. Lockman, Lucia Armillotta

Abstract: Hundreds of high-velocity atomic gas clouds exist above and below the Galactic Centre, with some containing a molecular component. However, the origin of these clouds in the Milky Way's wind is unclear. This paper presents new high-resolution MeerKAT observations of three atomic gas clouds and studies the relationship between the atomic and molecular phases at $\sim 1$ pc scales. The clouds' atomic hydrogen column densities, $N_{\mathrm{HI}}$, are less than a $\mbox{few}\times 10^{20}$ cm$^{-2}$, but the two clouds closest to the Galactic Centre nonetheless have detectable CO emission. This implies the presence of H$_{2}$ at levels of $N_{\mathrm{HI}}$ at least a factor of ten lower than in the typical Galactic interstellar medium. For the cloud closest to the Galactic Centre, there is little correlation between the $N_{\mathrm{HI}}$ and the probability that it will harbour detectable CO emissions. In contrast, for the intermediate cloud, detectable CO is heavily biased toward the highest values of $N_{\mathrm{HI}}$. The cloud most distant from the Galactic Centre has no detectable CO at similar $N_{\mathrm{HI}}$ values. Moreover, we find that the two clouds with detectable CO are too molecule-rich to be in chemical equilibrium, given the depths of their atomic shielding layers, which suggests a scenario whereby these clouds consist of pre-existing molecular gas from the disc that the Galactic wind has swept up, and that is dissociating into atomic hydrogen as it flows away from the Galaxy. We estimate that entrained molecular material of this type has a $\sim \mathrm{few}-10$ Myr lifetime before photodissociating.

5.Origin of neutron capture elements with the Gaia-ESO survey: the evolution of s- and r-process elements across the Milky Way

Authors:Marta Molero, Laura Magrini, Francesca Matteucci, Donatella Romano, Marco Palla, Gabriele Cescutti, Carlos Viscasillas Vázquez, Emanuele Spitoni

Abstract: We study the abundance patterns and the radial gradients of s-process elements (Y, Zr, Ba, La and Ce), r-process elements (Eu) and mixed-process elements (Mo, Nd and Pr) in the Galactic thin disc by means of a detailed two-infall chemical evolution model for the Milky Way with state-of-the-art nucleosynthesis prescriptions. We consider r-process nucleosynthesis from merging neutron stars (MNS), magneto-rotational supernovae (MR-SNe) and s-process synthesis from low- and intermediate- mass stars (LIMS) and rotating massive stars. The predictions of our model are compared with data from the sixth data release of the Gaia-ESO survey, from which we consider 62 open clusters with age > 0.1 Gyr and 1300 Milky Way disc field stars. We conclude that: i) the [Eu/Fe] vs. [Fe/H] is reproduced by both a prompt and a delayed source, but the quick source completely dominates the Eu production; ii) rotation in massive stars contribute substantially to the s-process elements of the first peak, but MNS and MR-SNe are necessary in order to reproduce the observations; iii) due to the adopted yields, our model overpredicts Pr and underpredicts Nd, while the [Mo/Fe] vs. [Fe/H] is nicely reproduced. For the radial gradients, we conclude that: i) our predicted slope of the [Fe/H] gradient is in agreement with the one observed in open clusters by Gaia-ESO and other high-resolution spectroscopic surveys. ii) The predicted slope of the [Eu/H] radial gradient is steeper than the observed one, independently on how quick the production of Eu is. We discuss the possible causes of this discrepancy in terms of both different Galaxy formation scenarios and stellar radial migration effects. iii) For all the elements belonging to the second s-process peak (Ba, La, Ce) as well as for Pr, we predict a plateau at low Galactocentric distances, which is probably due to the enhanced enrichment from LIMS in the inner regions.

6.Star-formation-rate estimates from water emission

Authors:K. M. Dutkowska, L. E. Kristensen

Abstract: (Abridged) The star-formation rate (SFR) quantitatively describes the star-formation process in galaxies. Current ways to calibrate this rate do not usually employ observational methods accounting for the low-mass end of stellar populations as their signatures are too weak. Accessing the bulk of protostellar activity within galactic star-forming regions can be achieved by tracing signposts of ongoing star formation. One such signpost is molecular outflows, which are bright in molecular emission. We propose to utilize the protostellar outflow emission as a tracer of the SFR. In this work, we introduce a novel version of the galaxy-in-a-box model, which can be used to relate molecular emission from star formation in galaxies with the SFR. We measured the predicted para-H2O emission at 988 GHz and corresponding SFRs for galaxies with LFIR = $10^8$ - $10^{11}$ L$_\odot$ in a distance-independent manner, and compared them with expectations from observations. We evaluated the derived results by varying the star formation efficiency, the free-fall time scaling factor, and the initial mass function. For the chosen H2O transition, relying on the current Galactic observations and star formation properties, we are underestimating the total galactic emission, while overestimating the SFRs, particularly for more starburst-like configurations. The current version of the galaxy-in-a-box model accounts for a limited number of processes and configurations, that is, it focuses on ongoing star formation in massive young clusters in a spiral galaxy. Therefore, the inferred results, which underestimate the emission and overestimate the SFR, are not surprising: known sources of emission are not included in the model. To improve the results, the next version of the model needs to include a more detailed treatment of the entire galactic ecosystem and other processes that would contribute to the emission.

7.On the anti-correlation between pericentric distance and inner dark matter density of Milky Way's dwarf spheroidal galaxies

Authors:Salvador Cardona-Barrero, Giuseppina Battaglia, Carlo Nipoti, Arianna Di Cintio

Abstract: An anti-correlation between the central density of the dark matter halo ($\rho_{150,\ {\rm DM}}$) and the pericentric distances ($r_{p}$) of the Milky Way's (MW's) dwarf spheroidal galaxies (dSphs) has been reported in the literature. The existence and origin of such anti-correlation is however controversial, one possibility being that only the densest dSphs can survive the tidal field towards the centre of our Galaxy. In this work, we place particular emphasis on quantifying the statistical significance of such anti-correlation, by using available literature data in order to explore its robustness under different assumptions on the MW gravitational potential, and for various derivations of $\rho_{150}$ and $r_{p}$. We consider models in which the MW is isolated and has a low ($8.8\times10^{11}\,M_{\odot}$) and high ($1.6\times10^{12}\, M_{\odot}$) halo mass, respectively, as well as configurations in which the MW's potential is perturbed by a Large Magellanic Cloud (LMC) infall. We find that, while data generally support models in which the dSphs' central DM density decreases as a function of their pericentric radius, this anti-correlation is statistically significant at $3\sigma$ level only in $\sim$12$\%$ of the combinations of $\rho_{150}$ and $r_{p}$ explored. Moreover, including the impact of the LMC's infall onto the MW weakens or even washes away this anti-correlation, with respect to models in which the MW is isolated. Our results suggest that the strength and existence of such anti-correlation is still debatable: exploring it with high-resolution simulations including baryonic physics and different DM flavours will help us to understand its emergence.

8.Towards discovery of gravitationally lensed explosive transients: the brightest galaxies in massive galaxy clusters from Planck-SZ2

Authors:Joshua C. Smith, Dan Ryczanowski, Matteo Bianconi, Denisa Cristescu, Sivani Harisankar, Saskia Hawkins, Megan L. James, Evan J. Ridley, Simon Wooding, Graham P. Smith

Abstract: We combine the Planck-SZ2 galaxy cluster catalogue with near-infrared photometry of galaxies from the VISTA Hemisphere Survey to identify candidate brightest cluster galaxies (BCGs) in 306 massive clusters in the Southern skies at redshifts of $z>0.1$. We find that 91% of these clusters have at least one candidate BCG within the 95% confidence interval on the cluster centers quoted by the Planck collaboration, providing reassurance that our analyses are statistically compatible, and find 92% to be reasonable candidates following a manual inspection. We make our catalog publicly available to assist colleagues interested in multi-wavelength studies of cluster cores, and the search for gravitationally lensed explosive transients in upcoming surveys including the Legacy Survey of Space and Time by the Vera C. Rubin Observatory.

9.LeMMINGs. VI. Connecting nuclear activity to bulge properties of active and inactive galaxies: radio scaling relations and galaxy environment

Authors:B. T. Dullo, J. H. Knapen, R. J. Beswick, R. D. Baldi, D. R. A. Williams, I. M. McHardy, D. A. Green, A. Gil de Paz, S. Aalto, A. Alberdi, M. K. Argo, H. -R. Klöckner, I. M. Mutie, D. J. Saikia, P. Saikia, I. R. Stevens

Abstract: Multiwavelength studies indicate that nuclear activity and bulge properties are closely related, but the details remain unclear. To study this further, we combine $Hubble~Space~Telescope$ bulge structural and photometric properties with 1.5 GHz, $e$-MERLIN nuclear radio continuum data from the LeMMINGs survey for a large sample of 173 `active' galaxies (LINERs and Seyferts) and `inactive' galaxies (H IIs and absorption line galaxies, ALGs). Dividing our sample into active and inactive, they define distinct (radio core luminosity)$-$(bulge mass), L_R,core-M_*,bulge, relations, with a mass turnover at M_*, bulge ~ 10^(9.8 +- 0.3) M_sun (supermassive black hole mass M_BH ~ 10^(6.8 +- 0.3) M_sun), which marks the transition from AGN-dominated nuclear radio emission in more massive bulges to that mainly driven by stellar processes in low-mass bulges. None of our 10/173 bulgeless galaxies host an AGN. The AGN fraction increases with increasing M_*, bulge such that f_optical_AGN $\propto$ M_*,bulge^(0.24 +- 0.06) and f_radio_AGN $\propto$ M_*,bulge^(0.24 +- 0.05). Between M_*,bulge ~ 10^8.5 and 10^11.3 M_sun, f_optical_AGN steadily rises from 15 +- 4 to 80 +- 5 per cent. We find that at fixed bulge mass, the radio loudness, nuclear radio activity and the (optical and radio) AGN fraction exhibit no dependence on environment. Radio-loud hosts preferentially possess an early-type morphology than radio-quiet hosts, the two types are however indistinguishable in terms of bulge S\'ersic index and ellipticity, while results on the bulge inner logarithmic profile slope are inconclusive. We finally discuss the importance of bulge mass in determining the AGN triggering processes, including potential implications for the nuclear radio emission in nearby galaxies.

10.Pure Spectroscopic Constraints on UV Luminosity Functions and Cosmic Star Formation History From 25 Galaxies at $z_\mathrm{spec}=8.61-13.20$ Confirmed with JWST/NIRSpec

Authors:Yuichi Harikane, Kimihiko Nakajima, Masami Ouchi, Hiroya Umeda, Yuki Isobe, Yoshiaki Ono, Yi Xu, Yechi Zhang

Abstract: We present pure spectroscopic constraints on the UV luminosity functions and cosmic star formation rate (SFR) densities from 25 galaxies at $z_\mathrm{spec}=8.61-13.20$. By reducing the JWST/NIRSpec spectra taken in multiple programs of ERO, ERS, GO, and DDT with our analysis technique, we independently confirm 16 galaxies at $z_\mathrm{spec}=8.61-11.40$ including new redshift determinations, and a bright interloper at $z_\mathrm{spec}=4.91$ that was claimed as a photometric candidate at z~16. In conjunction with nine galaxies at redshifts up to $z_\mathrm{spec}=13.20$ in the literature, we make a sample of 25 spectroscopically-confirmed galaxies in total and carefully derive the best estimates and lower limits of the UV luminosity functions. These UV luminosity function constraints are consistent with the previous photometric estimates within the uncertainties and indicate mild redshift evolution towards z~12 showing tensions with some theoretical models of rapid evolution. With these spectroscopic constraints, we obtain firm lower limits of the cosmic SFR densities and spectroscopically confirm a high SFR density at z~12 beyond the constant star-formation efficiency models, which supports earlier claims from the photometric studies. While there are no spectroscopically-confirmed galaxies with very large stellar masses violating the $\Lambda$CDM model due to the removal of the bright interloper, we confirm star-forming galaxies at $z_\mathrm{spec}=11-13$ with stellar masses much higher than model predictions. Our results indicate possibilities of high star-formation efficiency (>5%), hidden AGN, top-heavy initial mass function (possibly with Pop-III), and large scatter/variance. Having these successful and unsuccessful spectroscopy results, we suggest observational strategies for efficiently removing low redshift interlopers for future JWST programs.

11.The role of previous generations of stars in triggering star formation and driving gas dynamics

Authors:Nicholas P. Herrington, Clare L. Dobbs, Thomas J. R. Bending

Abstract: We present hydrodynamic and magnetohydrodynamic (MHD) simulations of sub galactic regions including photoionising and supernova feedack. We aim to improve the initial conditions of our region extraction models by including an initial population of stars. We also investigate the reliability of extracting regions in simulations, and show that with a good choice of region, results are comparable with using a larger region for the duration of our simulations. Simulations of star formation on molecular cloud scales typically start with a turbulent cloud of gas, from which stars form and then undergo feedback. In reality, a typical cloud or region within a galaxy may already include, or reside near some population of stars containing massive stars undergoing feedback. We find the main role of a prior population is triggering star formation, and contributing to gas dynamics. Early time supernova from the initial population are important in triggering new star formation and driving gas motions on larger scales above 100 pc, whilst the ionising feedback contribution from the initial population has less impact, since many members of the initial population have cleared out gas around them in the prior model. In terms of overall star formation rates though, the initial population has a relatively small effect, and the feedback does not for example suppress subsequent star formation. We find that MHD has a relatively larger impact than initial conditions, reducing the star formation rate by a factor of 3 at later times.

12.A Gaia Data Release 3 View on the Tip of the Red Giant Branch Luminosity

Authors:Siyang Li, Stefano Casertano, Adam G. Riess

Abstract: The tip of the red giant branch (TRGB) is a standard candle that can be used to help refine the determination of the Hubble constant. $Gaia$ Data Release 3 (DR3) provides synthetic photometry constructed from low-resolution BP/RP spectra for Milky Way field stars that can be used to directly calibrate the luminosity of the TRGB in the Johnson-Cousins I band, where the TRGB is least sensitive to metallicity. We calibrate the TRGB luminosity using a two-dimensional maximum likelihood algorithm with field stars and $Gaia$ synthetic photometry and parallaxes. For a high-contrast and low-contrast break (characterized by the values of the contrast parameter $ R$ or the magnitude of the break $ \beta $), we find $M^{TRGB}_I$ =$-4.02$ and $-3.92$ mag respectively, or a midpoint of $-3.970$ $^{+0.042} _{-0.024}$ (sys) $\pm$ $0.062$ (stat) mag. This measurement improves upon the TRGB measurement from Li et al. (2022), as the higher precision photometry based on $ Gaia $ DR3 allows us to constrain two additional free parameters of the luminosity function. We also investigate the possibility of using $Gaia$ DR3 synthetic photometry to calibrate the TRGB luminosity with $\omega$ Centauri, but find evidence of blending within the inner region for cluster member photometry that precludes accurate calibration with $Gaia$ DR3 photometry. We instead provide an updated TRGB measurement of $m^{TRGB}_I$ = $ 9.82 \pm 0.04$ mag in $\omega$ Centauri using ground-based photometry from the most recent version of the database described in Stetson et al. (2019), which gives $M^{TRGB}_I$ = $-3.97$ $\pm$ $0.04$ (stat) $\pm$ 0.10 (sys) mag when tied to the $Gaia$ EDR3 parallax distance from the consensus of Vasiliev & Baumgardt (2021), Soltis et al. (2021), and Ma\'{i}z Apell\'{a}niz et al. (2022a).

1.Photometric and Kinematic study of the open cluster NGC 1027

Authors:Apara Tripathi, Neelam Panwar, Saurabh Sharma, Brijesh Kumar, Shantanu Rastogi

Abstract: We present photometric and kinematic analysis of an intermediate age open cluster NGC 1027 using $UBV(RI)_c$ and Gaia Early Data Release 3 (EDR3) data. Structural and fundamental parameters such as cluster center, cluster extent, reddening, age and distance are estimated in this study. Cluster center is found about 2 arcmin away from the center reported earlier. Radius has been estimated to be about 8.00 arcmin(2.65pc). Using proper motion Gaia EDR3 data, membership probabilities has been derived for the stars in the region of cluster radius. We find mean proper motion of the cluster to be $\sim$(-0.84, 2.04) mas yr$^{-1}$ in (RA, DEC). We find 217 most probable (P$_\mu>$ 70\%) cluster members with mean parallax 0.892 $\pm$ 0.088 mas. Out of these, 160 members have counterparts in our optical observations. Few stars having P$_\mu>$ 70\% are found out of the cluster radius showing imprints of dynamical evolution. The color-color and color-magnitude diagrams for the cluster members found within 8.00 arcmin have been constructed using $UBV(RI)_c$ photometry and Gaia EDR3 data. This yields a reddening E($B$-$V$) $\sim$ 0.36 mag, age $\sim$ 130 Myr and distance $\sim$ 1.14 kpc. The mass function slope in the cluster region is $\Gamma$ $\sim$ -1.46 $\pm$ 0.15, which is similar to other Galactic open clusters. The dynamical study shows lack of faint stars in its inner region leading to mass segregation effect. A comparison of dynamical age with cluster age indicates that NGC 1027 is a dynamically relaxed cluster suggesting that mass segregation may be imprint of its dynamical relaxation.

2.Fuzzy dark matter confronts rotation curves of nearby dwarf irregular galaxies

Authors:Andrés Bañares-Hernández, Andrés Castillo, Jorge Martin Camalich, Giuliano Iorio

Abstract: We investigate phenomenologically the viability of fuzzy dark matter (FDM). We do this by confronting the predictions of the model, in particular the formation of a solitonic core at the centre of dark matter haloes, with a homogeneous and robust sample of high-resolution rotation curves from the ``LITTLE THINGS in 3D'' catalog. This comprises a collection of isolated, dark matter dominated dwarf-irregular galaxies that provides an optimal benchmark for cosmological studies. We use a statistical framework based on Markov-Chain Monte Carlo techniques that allows us to extract relevant parameters such as the axion mass, the mass of the solitonic core, the mass of the dark matter halo and its concentration parameter with a rather loose set of priors except for the implementation of a core-halo relation that is predicted by simulations. The results of the fits are used to perform various diagnostics on the predictions of the model. FDM provides an excellent fit to the rotation curves of the ``LITTLE THINGS in 3D'' catalog, with axion masses determined from different galaxies clustering around $m_a\approx2\times10^{-23}$ eV. However we find two major problems in our analysis. First, the data follow scaling relations of the properties of the core which are not consistent with the predictions of the soliton. This problem is particularly acute in the core radius - mass relation with a tension that, at face value, has a significance $\gtrsim5\sigma$. The second problem is related to the strong suppression of the linear power spectrum that is predicted by FDM for the axion mass preferred by the data. This can be constrained very conservatively by the galaxy counts in our sample, which leads to a tension exceeding again $5\sigma$. We estimate the effects of baryons in our analysis and discuss whether they could alleviate the tensions of the model with observations.

3.Finding AGN remnant candidates based on radio morphology with machine learning

Authors:Rafael I. J. Mostert, Raffaella Morganti, Marisa Brienza, Kenneth J. Duncan, Martijn S. S. L. Oei, Huub J. A. Rottgering, Lara Alegre, Martin J. Hardcastle, Nika Jurlin

Abstract: Remnant radio galaxies represent the dying phase of radio-loud active galactic nuclei (AGN). Large samples of remnant radio galaxies are important for quantifying the radio galaxy life cycle. The remnants of radio-loud AGN can be identified in radio sky surveys based on their spectral index, or, complementary, through visual inspection based on their radio morphology. However, this is extremely time-consuming when applied to the new large and sensitive radio surveys. Here we aim to reduce the amount of visual inspection required to find AGN remnants based on their morphology, through supervised machine learning trained on an existing sample of remnant candidates. For a dataset of 4107 radio sources, with angular sizes larger than 60 arcsec, from the LOw Frequency ARray (LOFAR) Two-Metre Sky Survey second data release (LoTSS-DR2), we started with 151 radio sources that were visually classified as 'AGN remnant candidate'. We derived a wide range of morphological features for all radio sources from their corresponding Stokes-I images: from simple source catalogue-derived properties, to clustered Haralick-features, and self-organising map (SOM) derived morphological features. We trained a random forest classifier to separate the 'AGN remnant candidates' from the not yet inspected sources. The SOM-derived features and the total to peak flux ratio of a source are shown to be most salient to the classifier. We estimate that $31\pm5\%$ of sources with positive predictions from our classifier will be labelled 'AGN remnant candidates' upon visual inspection, while we estimate the upper bound of the $95\%$ confidence interval for 'AGN remnant candidates' in the negative predictions at $8\%$. Visual inspection of just the positive predictions reduces the number of radio sources requiring visual inspection by $73\%$.

4.Highly structured turbulence in high-mass star formation: an evolved infrared dark cloud G35.20-0.74 N

Authors:Chao Wang, Ke Wang

Abstract: Context. Massive stars are generally believed to form in supersonic turbulent environment. However, recent observations have challenged this traditional view. High spatial and spectral resolution observations of the Orion Molecular Cloud and an infrared dark cloud G35.39 show a resolution-dependent turbulence, and that high-mass stars are forming exclusively in subsonic to transonic cores in those clouds. These studies demand a re-evaluation of the role of the turbulence in massive star formation. Aims. We aim to study the turbulence in a typical massive star-forming region G35.20-0.74 N with a sufficient spatial resolution to resolve the thermal Jeans length, and a spectral resolution to resolve the thermal linewidth. Methods. We use the ALMA dust continuum emission to resolve fragmentation, JVLA 1.2 cm continuum to trace ionized gas, and JVLA NH3 (1,1) to (7,7) inversion transition lines to trace linewidth, temperature, and dynamics. We fit those lines and remove line broadening due to channel width, thermal pressure, and velocity gradient to obtain a clean map of intrinsic turbulence. Results. We find that (1) the turbulence in G35.20 is overall supersonic, with mean and median Mach numbers 3.7 and 2.8, respectively. (2) Mach number decreases from 6-7 at 0.1 pc scale to <3 towards the central cores at 0.01 pc scale. (3) The central ALMA cores appear to be decoupled form the host filament, evident by an opposite velocity gradient and significantly reduced turbulence. Because of intense star formation activities in G35.20 (as compared to the relatively young and quiescent IRDC G35.39), the supersonic turbulence is likely replenished by protostellar outflows. G35.20 is, thus, representative of an evolved form of IRDC G35.39. More observations of a sample of IRDCs are highly demanded to further investigate the role of turbulence in initial conditions for the massive star formation.

5.New Deformed Heisenberg Algebra from the $μ$-Deformed Model of Dark Matter

Authors:A. M. Gavrilik, I. I. Kachurik, A. V. Nazarenko

Abstract: Recently, the $\mu$-deformation-based approach to modeling dark matter, which exploits $\mu$-deformed thermodynamics, was extended to the study of galaxy halo density profile and of the rotation curves of a number of (dwarf or low brightness) galaxies. For that goal, $\mu$-deformed analogs of the Lane--Emden equation (LEE) have been proposed, and their solutions describing density profiles obtained. There are two seemingly different versions of $\mu$-deformed LEE which possess the same solution, and so we deal with their equivalence. From the latter property we derive new, rather unusual, $\mu$-deformed Heisenberg algebra (HA) for the position and momentum operators, and present the $\mu$-HA in few possible forms (each one at $\mu\to0$ recovers usual HA). The generalized uncertainty relation linked with the new $\mu$-HA is studied, along with its interesting implications including the appearance of the quadruple of both maximal and minimal lengths and momenta.

6.In pursuit of giants: II. Evolution of dusty quiescent galaxies over the last six billion years from the hCOSMOS survey

Authors:Darko Donevski, Ivana Damjanov, Ambra Nanni, Allison Man, Marika Giulietti, Michael Romano, Andrea Lapi, Desika Narayanan, Romeel Davé, Irene Shivaei, Jubee Sohn, Junais, Lara Pantoni, Qi Li

Abstract: Quantifying changes in galaxies' interstellar medium (ISM) abundance after quenching star formation is an important aspect of galaxy evolution, but it is poorly constrained beyond the local universe. We characterise the dust-related properties in 548 quiescent galaxies observed at $0.1<z<0.6$ as part of the hCOSMOS spectroscopic survey. This is the largest sample of quiescent galaxies at intermediate redshifts, for which the co-evolution of dust, metals and stars have been estimated. We reveal the complex relations between the key markers of galaxies' dust life-cycles, such as specific dust mass ($M_{\rm dust}$/$M_{\rm \star}$), with gas-metallicity ($Z_{\rm gas}$), time since quenching ($t_{\rm quench}$), stellar age and size. We find morphology to be important factor of a large scatter ($\sim2$ orders of magnitude) in $M_{\rm dust}/M_{\rm \star}$. Through modelling the star formation histories of our objects, we derive a broad dynamical range of post-quenching timescales ($60\:\rm Myr<t_{\rm quench}<3.2\:\rm Gyr$). We find that $M_{\rm dust}/M_{\rm \star}$ is the highest in recently quenched systems ($t_{\rm quench}<500$ Myr), but its further evolution is non-monotonic as a consequence of diverse pathways for prolonged dust formation, or removal on various timescales. Our data are well reproduced by the SIMBA cosmological simulation and chemical models that include dust growth in the ISM. While this process is prevalent in dusty quiescent galaxies, $\sim15\%$ of objects show signs of external dust acquisition, most likely via minor mergers. Our results strongly suggest that prolonged dust production on a timescale $0.5-1\:\rm Gyr$ since quenching may be common in dusty quiescent galaxies at intermediate redshifts, even if their gas reservoirs are heavily exhausted (i.e., cold gas fraction $<1-5\%$).

7.The diffuse radio emission in the high-redshift cluster PSZ2 G091.83+26.11: total intensity and polarisation analysis with Very Large Array 1-4 GHz observations

Authors:G. Di Gennaro, M. Brüggen, R. J. van Weeren, A. Simionescu, G. Brunetti, R. Cassano, W. R. Forman, M. Hoeft, A. Ignesti, H. J. A. Röttgering, T. W. Shimwell

Abstract: We present the peculiar case of PSZ2G091.83+26.11 at z=0.822. This cluster hosts a Mpc-scale radio halo and an elongated radio source, whose location with the respect to the intracluster medium (ICM) distribution and to the cluster centre is not consistent with a simple merger scenario. We use VLA data at 1-4 GHz to investigate the spectral and polarisation properties of the diffuse radio emission. We combine them with previously published data from LOFAR n the 120-168 MHz band, and from the uGMRT at 250-500 and 550-900 MHz. We also complement the radio data with Chandra X-ray observations to compare the thermal and non-thermal emission of the cluster. The elongated radio emission is visible up to 3.0 GHz and has an integrated spectral index of $-1.24\pm0.03$, with a steepening from $-0.89\pm0.03$ to $-1.39\pm0.03$. These values correspond to Mach numbers $\mathcal{M}_{\rm radio,int}=3.0\pm0.19$ and $\mathcal{M}_{\rm radio,inj}=2.48\pm0.15$. Chandra data reveals a surface brightness discontinuity at the location of the radio source, with a compression factor of $\mathcal{C}=2.22^{+0.39}_{-0.30}$ (i.e. $\mathcal{M}_{\rm Xray}=1.93^{+0.42}_{-0.32}$). We also find that the source is polarised at GHz frequencies. We estimate an intrinsic polarisation fraction of $\sim0.2$, a Rotation Measure of $\sim50~{\rm rad~m^{-2}}$ (including the Galactic contribution) and an external depolarisation of $\sim60~{\rm rad~m^{-2}}$. The $B$-vectors are aligned with the major axis of the source, suggesting magnetic field compression. Hence, we classify this source as a radio relic. We also find a linear/super-linear correlation between the non-thermal and thermal emission. We propose an off-axis merger and/or multiple merger events to explain the position and orientation of the relic. Given the properties of the radio relic, we speculate that PSZ2G091.83+26.11 is in a fairly young merger state.

8.Sensitivity study of chemistry in AGB outflows using chemical kinetics

Authors:S. Maes, M. Van de Sande, T. Danilovich, F. De Ceuster, L. Decin

Abstract: Asymptotic Giant Branch (AGB) stars shed a significant amount of their mass in the form of a stellar wind, creating a vast circumstellar envelope (CSE). Owing to the ideal combination of relatively high densities and cool temperatures, CSEs serve as rich astrochemical laboratories. {While the chemical structure of AGB outflows has been modelled and analysed in detail for specific physical setups, there is a lack of understanding regarding the impact of changes in the physical environment on chemical abundances. A systematic sensitivity study is necessary to comprehend the nuances in the physical parameter space, given the complexity of the chemistry. This is crucial for estimating uncertainties associated with simulations and observations. In this work, we present the first sensitivity study of the impact of varying outflow densities and temperature profiles on the chemistry. With the use of a chemical kinetics model, we report on the uncertainty in abundances, given a specific uncertainty on the physical parameters. }Additionally, we analyse the molecular envelope extent of parent species and compare our findings to observational studies. Mapping the impact of differences in physical parameters throughout the CSE on the chemistry is a strong aid to observational studies.

9.Multi-phase gas nature in the sub-pc region of the active galactic nuclei I: Dynamical structures of dusty and dust-free outflow

Authors:Yuki Kudoh, Keiichi Wada, Nozomu Kawakatu, Mariko Nomura

Abstract: We investigated dusty and dust-free gas dynamics for a radiation-driven sub-pc scale outflow in an active galactic nucleus (AGN) associated with a supermassive black hole $10^7 M_\odot$ and bolometric luminosity $10^{44}$ erg s$^{-1}$ based on the two-dimensional radiation-hydrodynamic simulations. A radiation-driven ``lotus-like'' multi-shell outflow is launched from the inner part ($r \lesssim 0.04$ pc) of the geometrically thin disk, and it repeatedly and steadily produces shocks as mass accretion continues through the disk to the center. The shape of the dust sublimation radius is not spherical and depends on the angle ($\theta$) from the disk plane, reflecting the non-spherical radiation field and non-uniform dust-free gas. Moreover, we found that the sublimation radius of $\theta \sim 20$-$60$ deg varies on a timescale of several years. The ``inflow-induced outflow" contributes the obscuration of the nucleus in the sub-pc region. The column density of the dust-free gas is $N_{\rm H} \gtrsim 10^{22}$ cm$^{-2}$ for $r \lesssim 0.04$ pc. Gases near the disk plane ($\theta \lesssim 30$ degree) can be the origin of the Compton-thick component, which was suggested by the recent X-ray observations of AGNs. The dusty outflow from the sub-pc region can be also a source of material for the radiation-driven fountain for a larger scale.

10.The Loneliest Galaxies in the Universe: A GAMA and GalaxyZoo Study on Void Galaxy Morphology

Authors:Lori E. Porter Louisville, Benne W. Holwerda Louisville, Sandor Kruk MPE/ESA, Maritza Lara-López Madrid, Kevin Pimbblet Hull, Christopher Henry Louisville, Sarah Casura Hamburg, Lee Kelvin Princeton

Abstract: The large-scale structure (LSS) of the Universe is comprised of galaxy filaments, tendrils, and voids. The majority of the Universe's volume is taken up by these voids, which exist as underdense, but not empty, regions. The galaxies found inside these voids are expected to be some of the most isolated objects in the Universe. This study, using the Galaxy and Mass Assembly (GAMA) and Galaxy Zoo surveys, aims to investigate basic physical properties and morphology of void galaxies versus field (filament and tendril) galaxies. We use void galaxies with stellar masses of $9.35 < log(M/M_\odot) < 11.25$, and this sample is split by identifying two redshift-limited regions, 0 < z < 0.075, and, $0.075 < z < 0.15$. To find comparable objects in the sample of field galaxies from GAMA and Galaxy Zoo, we identify "twins" of void galaxies as field galaxies within $\pm$0.05 dex and $\pm$0.15 dex of M and specific star formation rate. We determine the statistical significance of our results using the Kolmogorov-Smirnov (KS) test. We see that void galaxies, in contrast with field galaxies, seem to be disk-dominated and have predominantly round bulges (with > 50 percent of the Galaxy Zoo citizen scientists agreeing that bulges are present).

1.Polarimetry of the potential binary supermassive black hole system in J1430+2303

Authors:F. Marin, D. Hutsemékers, I. Liodakis, R. Antonucci, N. Mandarakas, E. Lindfors, D. Blinov, T. Barnouin, D. Savic

Abstract: The growth of supermassive black holes (SMBHs) through merging has long been predicted but its detection remains elusive. However, a promising target has been discovered in the Seyfert-1 galaxy J1430+2303. If a binary system truly lies at the center of J1430+2303, the usual symmetry expected from pole-on views in active galactic nuclei (AGNs) responsible for the observed low ($\le$ 1\%) optical linear polarization in the continuum of these objects is expected to be broken. This should lead to higher-than-usual polarization degrees, together with time-dependent variations of the polarization signal. We used the specialized photopolarimeters RoboPol mounted on the 1.3m telescope at the Skinakas Observatory and the Alhambra Faint Object Spectrograph and Camera (ALFOSC) mounted on the 2.56m Nordic Optical Telescope (NOT) at the "Roque de los Muchachos" Observatory to measure the B-, V-, R-, and I-band polarization of J1430+2303. Observations were complemented using the FORS2 spectropolarimeter mounted on the VLT to acquire 3500 -- 8650 Angs polarized spectra. We compared our set of observations to Monte Carlo radiative-transfer predictions to look for the presence of a SMBH binary. The observed linear continuum polarization of J1430+2303 in the V and R bands is $\sim$ 0.4\% with an associated polarization angle of slightly larger than 0$^\circ$. We detected no significant changes in polarization or photometry between May, June, and July of 2022. In addition, there is no significant difference between the polarization of H$\alpha$ and the polarization of the continuum. A single SMBH at the center of an AGN model is able to reproduce the observed spectrum and polarization, while the binary hypothesis is rejected with a probability of $\sim$85\%.

2.Nitrogen pollution by metal enriched supermassive stars

Authors:Chris Nagele, Hideyuki Umeda

Abstract: GN-z11 is an unusually luminous high redshift galaxy which was recently observed to have strong nitrogen lines while at the same time lacking traditional signatures of AGN activity. These observations have been interpreted as a super-solar nitrogen abundance which is challenging to explain with standard stellar evolution and supernovae enrichment. We present simulations of four models of metal enriched supermassive stars after the zero age main sequence which produce super-solar nitrogen consistent with the observations of GN-z11. We then show that the most massive model ends its life in a violent explosion which results in even greater nitrogen pollution.

3.The Hα Luminosity Function of Galaxies at z {\sim} 4.5

Authors:Victoria Bollo, Valentino González, Mauro Stefanon, Pascal A. Oesch, Rychard J. Bouwens, Renske Smit, Garth D. Illingworth, Ivo Labbé

Abstract: We present the H{\alpha} luminosity function (LF) derived from a large sample of Lyman break galaxies at z {\sim} 4.5 over the GOODS-South and North fields. This study makes use of the new, full-depth Spitzer/IRAC [3.6] and [4.5] imaging from the GOODS Re-ionization Era wide-Area Treasury from the Spitzer program. The H{\alpha} flux is derived from the offset between the continuum flux estimated from the best-fit spectral energy distribution, and the observed photometry in IRAC [3.6]. From these measurements, we build the H{\alpha} LF and study its evolution providing the best constraints of this property at high redshift, where spectroscopy of H{\alpha} is not yet available. Schechter parameterizations of the H{\alpha} LF show a decreasing evolution of {\Phi^\star} with redshift, increasing evolution in L{^\star}, and no significant evolution in the faint-end slope at high z. We find that star formation rates (SFRs) derived from H{\alpha} are higher than those derived from the rest-frame UV for low SFR galaxies but the opposite happens for the highest SFRs. This can be explained by lower mass galaxies (also lower SFR) having, on average, rising star formation histories (SFHs), while at the highest masses the SFHs may be declining. The SFR function is steeper, and because of the excess SFR(H{\alpha}) compared to SFR(UV) at low SFRs, the SFR density estimated from H{\alpha} is higher than the previous estimates based on UV luminosities.

4.Differential reddening in the direction of 56 Galactic globular clusters

Authors:M. V. Legnardi, A. P. Milone, G. Cordoni, E. P. Lagioia, E. Dondoglio, A. F. Marino, S. Jang, A. Mohandasan, T. Ziliotto

Abstract: The presence of differential reddening in the direction of Galactic globular clusters (GCs) has proven to be a serious limitation in the traditional colour-magnitude diagram (CMD) analysis. Here, we estimate local reddening variations in the direction of 56 Galactic GCs. To do that, we use the public catalogs derived as part of the Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters, which include photometry in the F275W, F336W, F438W, F606W, and F814W filters. We correct photometry for differential reddening finding that for 21 out of 56 GCs the adopted correction procedure significantly improves the CMDs. Moreover, we measure the reddening law in the direction of these clusters finding that $R_{V}$ exhibits a high level of variability within the Galaxy, ranging from $\sim2.0$ to $\sim4.0$. The updated values of $R_{V}$ have been used to improve the determination of local reddening variations and derive high-resolution reddening maps in the direction of the 21 highly-reddened targets within our sample. To compare the results of the different clusters, we compute the 68$^{\rm th}$ percentile of the differential-reddening distribution, $\sigma_{\Delta A_{\rm F814W}}$. This quantity ranges from 0.003 mag to 0.030 mag and exhibits a significant anti-correlation with the absolute module of the Galactic latitude and a strong correlation with the average reddening in the direction of each cluster. Therefore, highly-reddened GCs located in the proximity of the Galactic plane typically show higher differential-reddening variations across their field of view.

5.The magnesium paradigm in IRC+10216: Discovery of MgC$_4$H$^+$, MgC$_3$N$^+$, MgC$_6$H$^+$, and MgC$_5$N$^+$

Authors:J. Cernicharo, C. Cabezas, J. R. Pardo, M. Agúndez, O. Roncero, B. Tercero, N. marcelino, M. Guélin, Y. Endo, P. deVicente

Abstract: We found four series of harmonically related lines in IRC\,+10216 with the Yebes\,40m and IRAM\,30m telescopes. The first series corresponds to a molecule with a rotational constant, $B$, of 1448.5994$\pm$0.0013 MHz and a distortion constant, $D$, of 63.45$\pm$1.15 Hz and covers upper quantum numbers from $J_u$=11 up to 33 (B1449). The second series is fitted with $B$=1446.9380$\pm$0.0098 MHz and $D$=91$\pm$23 Hz and covers upper quantum numbers from $J_u$=11 up to 17 (B1447). The third series is fitted with $B$=598.7495$\pm$0.0011 MHz and D=6.13$\pm$0.43 Hz and covers quantum numbers from $J_u$=26 up to 41 (B599). Finally, the frequencies of the last series of lines can be reproduced with $B$=594.3176$\pm$0.0026 MHz and $D$=4.92$\pm$1.16 Hz (B594). The large values of $D$ point toward four metal-bearing carriers. After exploring all plausible candidates containing Na, Al, Mg, and other metals, our ab initio calculations indicate that the cations MgC$_4$H$^+$, MgC$_3$N$^+$, MgC$_6$H$^+$, and MgC$_5$N$^+$ must be the carriers of B1449, B1447, B599, and B594, respectively. These cations could be formed by the radiative association of Mg$^+$ with C$_4$H, C$_3$N, C$_6$H, and C$_5$N, respectively. We calculated the radiative association rate coefficient of Mg$^+$ with C$_4$H, C$_3$N, C$_6$H, and C$_5$N and incorporated them in our chemical model. The results confirm that the Mg-bearing cations can be formed through these radiative association reactions in the outer layers of IRC\,+10216. This is the first time that cationic metal-bearing species have been found in space. These results provide a new paradigm on the reactivity of ionized metals with abundant radicals and open the door for further characterization of similar species in metal-rich astrophysical environments.

6.On the recent discovery claim of a new $z>7$ quasar

Authors:Sarah E. I. Bosman, Frederick B. Davies, Eduardo Bañados

Abstract: Koptelova et al. 2022 (K22) recently claimed a new quasar discovery at $z=7.46$. After careful consideration of the publicly-available data underlying K22's claim, we find that the observations were contaminated by a moving Solar System object, likely a main-belt asteroid. In the absence of the contaminated photometry, there is no evidence for the nearby, persistent WISE source being a high-redshift object; in fact, a detection of the source in DELS $z$-band rules out a redshift $z>7.3$. We present our findings as a cautionary tale of the dangers of passing asteroids for photometric selections.

7.Spectroscopic confirmation of CEERS NIRCam-selected galaxies at $\boldsymbol{z \simeq 8-10}$

Authors:Pablo Arrabal Haro, Mark Dickinson, Steven L. Finkelstein, Seiji Fujimoto, Vital Fernández, Jeyhan S. Kartaltepe, Intae Jung, Justin W. Cole, Denis Burgarella, Katherine Chworowsky, Taylor A. Hutchison, Alexa M. Morales, Casey Papovich, Raymond C. Simons, Ricardo O. Amorín, Bren E. Backhaus, Micaela B. Bagley, Laura Bisigello, Antonello Calabrò, Marco Castellano, Nikko J. Cleri, Romeel Davé, Avishai Dekel, Henry C. Ferguson, Adriano Fontana, Eric Gawiser, Mauro Giavalisco, Santosh Harish, Nimish P. Hathi, Michaela Hirschmann, Benne W. Holwerda, Marc Huertas-Company, Anton M. Koekemoer, Rebecca L. Larson, Ray A. Lucas, Bahram Mobasher, Pablo G. Pérez-González, Nor Pirzkal, Caitlin Rose, Paola Santini, Jonathan R. Trump, Alexander de la Vega, Xin Wang, Benjamin J. Weiner, Stephen M. Wilkins, Guang Yang, L. Y. Aaron Yung, Jorge A. Zavala

Abstract: We present JWST/NIRSpec prism spectroscopy of seven galaxies selected from the Cosmic Evolution Early Release Science Survey (CEERS) NIRCam imaging with photometric redshifts z_phot>8. We measure emission line redshifts of z=7.65 and 8.64 for two galaxies, and z=9.77(+0.37,-0.29) and 10.01(+0.14,-0.19) for two others via the detection of continuum breaks consistent with Lyman-alpha opacity from a mostly neutral intergalactic medium. The presence (absense) of strong breaks (strong emission lines) give high confidence that these two galaxies are at z>9.6, but the break-derived redshifts have large uncertainties given the low spectral resolution and relatively low signal-to-noise of the CEERS NIRSpec prism data. The two z~10 sources are relatively luminous (M_UV<-20), with blue continua (-2.3<beta<-1.9) and low dust attenuation (A_V=0.15(+0.3,-0.1)); and at least one of them has high stellar mass for a galaxy at that redshift (log(M_*/M_sol)=9.3(+0.2,-0.3)). Considered together with spectroscopic observations of other CEERS NIRCam-selected high-z galaxy candidates in the literature, we find a high rate of redshift confirmation and low rate of confirmed interlopers (8.3%). Ten out of 34 z>8 candidates with CEERS NIRSpec spectroscopy do not have secure redshifts, but the absence of emission lines in their spectra is consistent with redshifts z>9.6. We find that z>8 photometric redshifts are generally in agreement (within uncertainties) with the spectroscopic values. However, the photometric redshifts tend to be slightly overestimated (average Delta(z)=0.50+/-0.12), suggesting that current templates do not fully describe the spectra of very high-z sources. Overall, our results solidifies photometric evidence for a high space density of bright galaxies at z>8 compared to theoretical model predictions, and further disfavors an accelerated decline in the integrated UV luminosity density at z>8.

8.CEERS: Diversity of Lyman-Alpha Emitters during the Epoch of Reionization

Authors:Intae Jung, Steven L. Finkelstein, Pablo Arrabal Haro, Mark Dickinson, Henry C. Ferguson, Taylor A. Hutchison, Jeyhan S. Kartaltepe, Rebecca L. Larson, Raymond C. Simons, Casey Papovich, Hyunbae Park, Laura Pentericci, Jonathan R. Trump, Ricardo O. Amorin, Bren E. Backhaus, Caitlin M. Casey, Yingjie Cheng, Nikko J. Cleri, M. C. Cooper, Olivia R. Cooper, Jonathan P. Gardner, Eric Gawiser, Andrea Grazian, Nimish P. Hathi, Michaela Hirschmann, Anton M. Koekemoer, Ray A. Lucas, Bahram Mobasher, Swara Ravindranath, Amber N. Straughn, L. Y. Aaron Yung, Alexander de la Vega

Abstract: We analyze rest-frame ultraviolet to optical spectra of three $z\simeq7.47$ - $7.75$ galaxies whose Ly$\alpha$-emission lines were previously detected with Keck/MOSFIRE observations, using the JWST/NIRSpec observations from the Cosmic Evolution Early Release Science (CEERS) survey. From NIRSpec data, we confirm the systemic redshifts of these Ly$\alpha$ emitters, and emission-line ratio diagnostics indicate these galaxies were highly ionized and metal poor. We investigate Ly$\alpha$ line properties, including the line flux, velocity offset, and spatial extension. For the one galaxy where we have both NIRSpec and MOSFIRE measurements, we find a significant offset in their flux measurements ($\sim5\times$ greater in MOSFIRE) and a marginal difference in the velocity shifts. The simplest interpretation is that the Ly$\alpha$ emission is extended and not entirely encompassed by the NIRSpec slit. The cross-dispersion profiles in NIRSpec reveal that Ly$\alpha$ in one galaxy is significantly more extended than the non-resonant emission lines. We also compute the expected sizes of ionized bubbles that can be generated by the Ly$\alpha$ sources, discussing viable scenarios for the creation of sizable ionized bubbles ($>$1 physical Mpc). The source with the highest-ionization condition is possibly capable of ionizing its own bubble, while the other two do not appear to be capable of ionizing such a large region, requiring additional sources of ionizing photons. Therefore, the fact that we detect Ly$\alpha$ from these galaxies suggests diverse scenarios on escape of Ly$\alpha$ during the epoch of reionization. High spectral resolution spectra with JWST/NIRSpec will be extremely useful for constraining the physics of patchy reionization.

1.Differential reddening in the direction of 56 Galactic globular clusters

Authors:M. V. Legnardi, A. P. Milone, G. Cordoni, E. P. Lagioia, E. Dondoglio, A. F. Marino, S. Jang, A. Mohandasan, T. Ziliotto

Abstract: The presence of differential reddening in the direction of Galactic globular clusters (GCs) has proven to be a serious limitation in the traditional colour-magnitude diagram (CMD) analysis. Here, we estimate local reddening variations in the direction of 56 Galactic GCs. To do that, we use the public catalogs derived as part of the Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters, which include photometry in the F275W, F336W, F438W, F606W, and F814W filters. We correct photometry for differential reddening finding that for 21 out of 56 GCs the adopted correction procedure significantly improves the CMDs. Moreover, we measure the reddening law in the direction of these clusters finding that $R_{V}$ exhibits a high level of variability within the Galaxy, ranging from $\sim2.0$ to $\sim4.0$. The updated values of $R_{V}$ have been used to improve the determination of local reddening variations and derive high-resolution reddening maps in the direction of the 21 highly-reddened targets within our sample. To compare the results of the different clusters, we compute the 68$^{\rm th}$ percentile of the differential-reddening distribution, $\sigma_{\Delta A_{\rm F814W}}$. This quantity ranges from 0.003 mag to 0.030 mag and exhibits a significant anti-correlation with the absolute module of the Galactic latitude and a strong correlation with the average reddening in the direction of each cluster. Therefore, highly-reddened GCs located in the proximity of the Galactic plane typically show higher differential-reddening variations across their field of view.

2.The magnesium paradigm in IRC+10216: Discovery of MgC$_4$H$^+$, MgC$_3$N$^+$, MgC$_6$H$^+$, and MgC$_5$N$^+$

Authors:J. Cernicharo, C. Cabezas, J. R. Pardo, M. Agúndez, O. Roncero, B. Tercero, N. marcelino, M. Guélin, Y. Endo, P. deVicente

Abstract: We found four series of harmonically related lines in IRC\,+10216 with the Yebes\,40m and IRAM\,30m telescopes. The first series corresponds to a molecule with a rotational constant, $B$, of 1448.5994$\pm$0.0013 MHz and a distortion constant, $D$, of 63.45$\pm$1.15 Hz and covers upper quantum numbers from $J_u$=11 up to 33 (B1449). The second series is fitted with $B$=1446.9380$\pm$0.0098 MHz and $D$=91$\pm$23 Hz and covers upper quantum numbers from $J_u$=11 up to 17 (B1447). The third series is fitted with $B$=598.7495$\pm$0.0011 MHz and D=6.13$\pm$0.43 Hz and covers quantum numbers from $J_u$=26 up to 41 (B599). Finally, the frequencies of the last series of lines can be reproduced with $B$=594.3176$\pm$0.0026 MHz and $D$=4.92$\pm$1.16 Hz (B594). The large values of $D$ point toward four metal-bearing carriers. After exploring all plausible candidates containing Na, Al, Mg, and other metals, our ab initio calculations indicate that the cations MgC$_4$H$^+$, MgC$_3$N$^+$, MgC$_6$H$^+$, and MgC$_5$N$^+$ must be the carriers of B1449, B1447, B599, and B594, respectively. These cations could be formed by the radiative association of Mg$^+$ with C$_4$H, C$_3$N, C$_6$H, and C$_5$N, respectively. We calculated the radiative association rate coefficient of Mg$^+$ with C$_4$H, C$_3$N, C$_6$H, and C$_5$N and incorporated them in our chemical model. The results confirm that the Mg-bearing cations can be formed through these radiative association reactions in the outer layers of IRC\,+10216. This is the first time that cationic metal-bearing species have been found in space. These results provide a new paradigm on the reactivity of ionized metals with abundant radicals and open the door for further characterization of similar species in metal-rich astrophysical environments.

3.On the recent discovery claim of a new $z>7$ quasar

Authors:Sarah E. I. Bosman, Frederick B. Davies, Eduardo Bañados

Abstract: Koptelova et al. 2022 (K22) recently claimed a new quasar discovery at $z=7.46$. After careful consideration of the publicly-available data underlying K22's claim, we find that the observations were contaminated by a moving Solar System object, likely a main-belt asteroid. In the absence of the contaminated photometry, there is no evidence for the nearby, persistent WISE source being a high-redshift object; in fact, a detection of the source in DELS $z$-band rules out a redshift $z>7.3$. We present our findings as a cautionary tale of the dangers of passing asteroids for photometric selections.

4.Spectroscopic confirmation of CEERS NIRCam-selected galaxies at $\boldsymbol{z \simeq 8-10}$

Authors:Pablo Arrabal Haro, Mark Dickinson, Steven L. Finkelstein, Seiji Fujimoto, Vital Fernández, Jeyhan S. Kartaltepe, Intae Jung, Justin W. Cole, Denis Burgarella, Katherine Chworowsky, Taylor A. Hutchison, Alexa M. Morales, Casey Papovich, Raymond C. Simons, Ricardo O. Amorín, Bren E. Backhaus, Micaela B. Bagley, Laura Bisigello, Antonello Calabrò, Marco Castellano, Nikko J. Cleri, Romeel Davé, Avishai Dekel, Henry C. Ferguson, Adriano Fontana, Eric Gawiser, Mauro Giavalisco, Santosh Harish, Nimish P. Hathi, Michaela Hirschmann, Benne W. Holwerda, Marc Huertas-Company, Anton M. Koekemoer, Rebecca L. Larson, Ray A. Lucas, Bahram Mobasher, Pablo G. Pérez-González, Nor Pirzkal, Caitlin Rose, Paola Santini, Jonathan R. Trump, Alexander de la Vega, Xin Wang, Benjamin J. Weiner, Stephen M. Wilkins, Guang Yang, L. Y. Aaron Yung, Jorge A. Zavala

Abstract: We present JWST/NIRSpec prism spectroscopy of seven galaxies selected from the Cosmic Evolution Early Release Science Survey (CEERS) NIRCam imaging with photometric redshifts z_phot>8. We measure emission line redshifts of z=7.65 and 8.64 for two galaxies, and z=9.77(+0.37,-0.29) and 10.01(+0.14,-0.19) for two others via the detection of continuum breaks consistent with Lyman-alpha opacity from a mostly neutral intergalactic medium. The presence (absense) of strong breaks (strong emission lines) give high confidence that these two galaxies are at z>9.6, but the break-derived redshifts have large uncertainties given the low spectral resolution and relatively low signal-to-noise of the CEERS NIRSpec prism data. The two z~10 sources are relatively luminous (M_UV<-20), with blue continua (-2.3<beta<-1.9) and low dust attenuation (A_V=0.15(+0.3,-0.1)); and at least one of them has high stellar mass for a galaxy at that redshift (log(M_*/M_sol)=9.3(+0.2,-0.3)). Considered together with spectroscopic observations of other CEERS NIRCam-selected high-z galaxy candidates in the literature, we find a high rate of redshift confirmation and low rate of confirmed interlopers (8.3%). Ten out of 34 z>8 candidates with CEERS NIRSpec spectroscopy do not have secure redshifts, but the absence of emission lines in their spectra is consistent with redshifts z>9.6. We find that z>8 photometric redshifts are generally in agreement (within uncertainties) with the spectroscopic values. However, the photometric redshifts tend to be slightly overestimated (average Delta(z)=0.50+/-0.12), suggesting that current templates do not fully describe the spectra of very high-z sources. Overall, our results solidifies photometric evidence for a high space density of bright galaxies at z>8 compared to theoretical model predictions, and further disfavors an accelerated decline in the integrated UV luminosity density at z>8.

5.CEERS: Diversity of Lyman-Alpha Emitters during the Epoch of Reionization

Authors:Intae Jung, Steven L. Finkelstein, Pablo Arrabal Haro, Mark Dickinson, Henry C. Ferguson, Taylor A. Hutchison, Jeyhan S. Kartaltepe, Rebecca L. Larson, Raymond C. Simons, Casey Papovich, Hyunbae Park, Laura Pentericci, Jonathan R. Trump, Ricardo O. Amorin, Bren E. Backhaus, Caitlin M. Casey, Yingjie Cheng, Nikko J. Cleri, M. C. Cooper, Olivia R. Cooper, Jonathan P. Gardner, Eric Gawiser, Andrea Grazian, Nimish P. Hathi, Michaela Hirschmann, Anton M. Koekemoer, Ray A. Lucas, Bahram Mobasher, Swara Ravindranath, Amber N. Straughn, L. Y. Aaron Yung, Alexander de la Vega

Abstract: We analyze rest-frame ultraviolet to optical spectra of three $z\simeq7.47$ - $7.75$ galaxies whose Ly$\alpha$-emission lines were previously detected with Keck/MOSFIRE observations, using the JWST/NIRSpec observations from the Cosmic Evolution Early Release Science (CEERS) survey. From NIRSpec data, we confirm the systemic redshifts of these Ly$\alpha$ emitters, and emission-line ratio diagnostics indicate these galaxies were highly ionized and metal poor. We investigate Ly$\alpha$ line properties, including the line flux, velocity offset, and spatial extension. For the one galaxy where we have both NIRSpec and MOSFIRE measurements, we find a significant offset in their flux measurements ($\sim5\times$ greater in MOSFIRE) and a marginal difference in the velocity shifts. The simplest interpretation is that the Ly$\alpha$ emission is extended and not entirely encompassed by the NIRSpec slit. The cross-dispersion profiles in NIRSpec reveal that Ly$\alpha$ in one galaxy is significantly more extended than the non-resonant emission lines. We also compute the expected sizes of ionized bubbles that can be generated by the Ly$\alpha$ sources, discussing viable scenarios for the creation of sizable ionized bubbles ($>$1 physical Mpc). The source with the highest-ionization condition is possibly capable of ionizing its own bubble, while the other two do not appear to be capable of ionizing such a large region, requiring additional sources of ionizing photons. Therefore, the fact that we detect Ly$\alpha$ from these galaxies suggests diverse scenarios on escape of Ly$\alpha$ during the epoch of reionization. High spectral resolution spectra with JWST/NIRSpec will be extremely useful for constraining the physics of patchy reionization.

1.The ISM scaling relations using inner HI and an application of estimating dust mass

Authors:Fujia Li, Jing Wang, Fengwei Xu, Xu Kong, Xinkai Chen, Zesen Lin, Shun Wang

Abstract: We select a disk-like galaxy sample with observations of the $HI$, $H_{2}$ and dust from Herschel Reference Survey (HRS), and derive inner HI masses within the optical radius. We find that the inner gas-to-dust ratio is almost independent of gas-phase metallicity, and confirm that the inner gas mass ($HI$+$H_{2}$) shows tighter relationship with dust mass and monochromatic 500 $\mu m$ luminosity than the integral gas mass. It supports that dust is more closely associated with co-spatial cold gas than the overall cold gas. Based on the newly calibrated relationship between inner gas mass and dust mass, we predict dust masses for disk-dominated galaxies from the xCOLD GASS sample. The predicted dust masses show scaling relations consistent with fiducial ones in the literature, supporting their robustness. Additionally, we find that at a given dust mass and star formation rate (SFR), the galactic WISE W3 luminosities show significant dependence on the [NII] luminosity and the stellar mass surface density. Such dependence highlights the caveat of using the W3 luminosity as integral SFR indicator, and is consistent with findings of studies which target star-forming regions in more nearby galaxies and accurately derive dust masses based on mapping-mode spectroscopy.

2.JWST and ALMA imaging of dust-obscured, massive substructures in a typical $z \sim 3$ star-forming disk galaxy

Authors:Wiphu Rujopakarn, Christina C. Williams, Emanuele Daddi, Malte Schramm, Fengwu Sun, Stacey Alberts, George H. Rieke, Qing-Hua Tan, Sandro Tacchella, Mauro Giavalisco, John D. Silverman

Abstract: We present an identification of dust-attenuated star-forming galactic-disk substructures in a typical star-forming galaxy (SFG), UDF2, at $z = 2.696$. To date, substructures containing significant buildup of stellar mass and actively forming stars have yet to be found in typical (i.e., main-sequence) SFGs at $z > 2$. This is due to the strong dust attenuation common in massive galaxies at the epoch and the scarcity of high-resolution, high-sensitivity extinction-independent imaging. To search for disk substructures, we subtracted the central stellar-mass disk from the JWST/NIRCam rest-frame 1.2 $\mu$m image ($0.13''$ resolution) and subtracted, in the visibility plane, the central starburst disk from ALMA rest-frame 240 $\mu$m observations ($0.03''$ resolution). The residual images revealed substructures at rest-frame 1.2 $\mu$m co-located with those found at rest-frame 240 $\mu$m, $\simeq 2$ kpc away from the galactic center. The largest substructure contains $\simeq20$% of the total stellar mass and $\simeq5$% of the total SFR of the galaxy. While UDF2 exhibits a kinematically-ordered velocity field of molecular gas consistent with a secularly evolving disk, more sensitive observations are required to characterize the nature and the origin of this substructure (spiral arms, minor merger, or other types of disk instabilities). UDF2 resides in an overdense region ($N \geqslant 4$ massive galaxies within 70 kpc projected distance at $z=2.690-2.697$) and the substructures may be associated with interaction-induced instabilities. Importantly, a statistical sample of such substructures identified with JWST and ALMA could play a key role in bridging the gap between the bulge-forming starburst and the rest of the galaxy.

3.(SHERRY) JCMT-SCUBA2 High Redshift Bright Quasar Survey -- II: the environment of z~6 quasars in sub-millimeter band

Authors:Qiong Li, Ran Wang, Xiaohui Fan, Xue-Bing Wu, Linhua Jiang, Eduardo Bañados, Bram Venemans, Yali Shao, Jianan Li, Jeff Wagg, Roberto Decarli, Chiara Mazzucchelli, Alain Omont, Frank Bertoldi, Sean Johnson, Christopher J. Conselice

Abstract: The formation of the first supermassive black holes is expected to have occurred in some most pronounced matter and galaxy overdensities in the early universe. We have conducted a sub-mm wavelength continuum survey of 54 $z\sim6$ quasars using the Submillimeter Common-User Bolometre Array-2 (SCUBA2) on the James Clerk Maxwell Telescope (JCMT) to study the environments around $z \sim 6$ quasars. We identified 170 submillimeter galaxies (SMGs) with above 3.5$\sigma$ detections at 450 or 850 \um\, maps. Their FIR luminosities are 2.2 - 6.4 $\times$ 10$^{12} L_{\odot}$, and star formation rates are $\sim$ 400 - 1200 M$_{\odot}$ yr$^{-1}$. We also calculated the SMGs differential and cumulative number counts in a combined area of $\sim$ 620 arcmin$^2$. To a $4\sigma$ detection (at $\sim$ 5.5 mJy), SMGs overdensity is $0.68^{+0.21}_{-0.19}$($\pm0.19$), exceeding the blank field source counts by a factor of 1.68. We find that 13/54 quasars show overdensities (at $\sim$ 5.5 mJy) of $\delta_{SMG}\sim$ 1.5 - 5.4. The combined area of these 13 quasars exceeds the blank field counts with the overdensity to 5.5 mJy of \dsmg $\sim$ $2.46^{+0.64}_{-0.55}$($\pm0.25$) in the regions of $\sim$ 150 arcmin$^2$. However, the excess is insignificant on the bright end (e.g., 7.5 mJy). We also compare results with previous environmental studies of Lyman alpha emitters (LAEs) and Lyman-Break Galaxies (LBGs) on a similar scale. Our survey presents the first systematic study of the environment of quasars at $z\sim6$. The newly discovered SMGs provide essential candidates for follow-up spectroscopic observations to test whether they reside in the same large-scale structures as the quasars and search for protoclusters at an early epoch.

4.The Physical Drivers and Observational Tracers of CO-to-H2 Conversion Factor Variations in Nearby Barred Galaxy Centers

Authors:Yu-Hsuan Teng, Karin M. Sandstrom, Jiayi Sun, Munan Gong, Alberto D. Bolatto, I-Da Chiang, Adam K. Leroy, Antonio Usero, Simon C. O. Glover, Ralf S. Klessen, Daizhong Liu, Miguel Querejeta, Eva Schinnerer, Frank Bigiel, Yixian Cao, Melanie Chevance, Cosima Eibensteiner, Kathryn Grasha, Frank P. Israel, Eric J. Murphy, Lukas Neumann, Hsi-An Pan, Francesca Pinna, Mattia C. Sormani, J. D. T. Smith, Fabian Walter, Thomas G. Williams

Abstract: The CO-to-H$_2$ conversion factor ($\alpha_\rm{CO}$) is central to measuring the amount and properties of molecular gas. It is known to vary with environmental conditions, and previous studies have revealed lower $\alpha_\rm{CO}$ in the centers of some barred galaxies on kpc scales. To unveil the physical drivers of such variations, we obtained ALMA Band 3, 6, and 7 observations toward the inner 2 kpc of NGC 3627 and NGC 4321 tracing $^{12}$CO, $^{13}$CO, and C$^{18}$O lines on 100 pc scales. Our multi-line modeling and Bayesian likelihood analysis of these datasets reveal variations of molecular gas density, temperature, optical depth, and velocity dispersion, which are among the key drivers of $\alpha_\rm{CO}$. The central 300 pc nuclei in both galaxies show strong enhancement of temperature $T_\rm{k}>100$ K and density $n_\rm{H_2}>10^3$ cm$^{-3}$. Assuming a CO-to-H$_2$ abundance of $3\times10^{-4}$, we derive 4-15 times lower $\alpha_\rm{CO}$ than the Galactic value across our maps, which agrees well with previous kpc-scale measurements. Combining the results with our previous work on NGC 3351, we find a strong correlation of $\alpha_\rm{CO}$ with low-J $^{12}$CO optical depths ($\tau_\rm{CO}$), as well as an anti-correlation with $T_\rm{k}$. The $\tau_\rm{CO}$ correlation explains most of the $\alpha_\rm{CO}$ variation in the three galaxy centers, whereas changes in $T_\rm{k}$ influence $\alpha_\rm{CO}$ to second order. Overall, the observed line width and $^{12}$CO/$^{13}$CO 2-1 line ratio correlate with $\tau_\rm{CO}$ variation in these centers, and thus they are useful observational indicators for $\alpha_\rm{CO}$ variation. We also test current simulation-based $\alpha_\rm{CO}$ prescriptions and find a systematic overprediction, which likely originates from the mismatch of gas conditions between our data and the simulations.

5.A Comparison of Outflow Properties in AGN Dwarfs vs. Star Forming Dwarfs

Authors:Archana Aravindan, Weizhe Liu, Gabriela Canalizo, Sylvain Veilleux, Thomas Bohn, Remington O. Sexton, David S. N. Rupke, Vivian U

Abstract: Feedback likely plays a crucial role in resolving discrepancies between observed and theoretical predictions of dwarf galaxy properties. Stellar feedback was once believed to be sufficient to explain these discrepancies, but it has thus far failed to fully reconcile theory and observations. The recent discovery of energetic galaxy-wide outflows in dwarf galaxies hosting Active Galactic Nuclei (AGN) suggests that AGN feedback may have a larger role in the evolution of dwarf galaxies than previously suspected. In order to assess the relative importance of stellar versus AGN feedback in these galaxies, we perform a detailed Keck/KCWI optical integral field spectroscopic study of a sample of low-redshift star-forming (SF) dwarf galaxies that show outflows in ionized gas in their SDSS spectra. We characterize the outflows and compare them to observations of AGN-driven outflows in dwarfs. We find that SF dwarfs have outflow components that have comparable widths (W$_{80}$) to those of outflows in AGN dwarfs, but are much less blue-shifted, indicating that SF dwarfs have significantly slower outflows than their AGN counterparts. The outflows in SF dwarfs are spatially resolved and significantly more extended than those in AGN dwarfs. The mass loss rates, momentum and energy rates of SF-driven outflows are much lower than those of AGN-driven outflows. Our results indicate that AGN feedback in the form of gas outflows may play an important role in dwarf galaxies and should be considered along with SF feedback in models of dwarf galaxy evolution.

6.Shedding New Light on Weak Emission-Line Quasars in the C$_{\rm IV}$-H$β$ Parameter Space

Authors:Trung Ha U. North Texas, Cooper Dix U. North Texas, Brandon M. Matthews U. North Texas, Ohad Shemmer U. North Texas, Michael S. Brotherton U. Wyoming, Adam Myers U. Wyoming, Gordon T. Richards Drexel U, Jaya Maithil CfA, Scott F. Anderson U. Washington, W. N. Brandt Penn State U, Aleksandar M. Diamond-Stanic Bates College, Xiaohui Fan U. Arizona, Sarah C. Gallagher U. Western Ontario, Richard F. Green U. Arizona, Paulina Lira U. Chile, Bin Luo Nanjing U, Hagai Netzer Tel Aviv U, Richard Plotkin U. Nevada-Reno, Jessie C. Runnoe Vanderbilt U, Donald P. Schneider Penn State U, Michael A. Strauss Princeton U, Benny Trakhtenbrot Tel Aviv U, Jianfeng Wu Xiamen U

Abstract: Weak emission-line quasars (WLQs) are a subset of Type 1 quasars that exhibit extremely weak Ly$\alpha +$N V $\lambda$1240 and/or C IV $\lambda$1549 emission lines. We investigate the relationship between emission-line properties and accretion rate for a sample of 230 `ordinary' Type 1 quasars and 18 WLQs at $z < 0.5$ and $1.5 < z < 3.5$ that have rest-frame ultraviolet and optical spectral measurements. We apply a correction to the H$\beta$-based black-hole mass ($M_{\rm BH}$) estimates of these quasars using the strength of the optical Fe II emission. We confirm previous findings that WLQs' $M_{\rm BH}$ values are overestimated by up to an order of magnitude using the traditional broad emission-line region size-luminosity relation. With this $M_{\rm BH}$ correction, we find a significant correlation between H$\beta$-based Eddington luminosity ratios and a combination of the rest-frame C IV equivalent width and C IV blueshift with respect to the systemic redshift. This correlation holds for both ordinary quasars and WLQs, which suggests that the two-dimensional C IV parameter space can serve as an indicator of accretion rate in all Type 1 quasars across a wide range of spectral properties.

7.The impact of environmental effects on AGN: a decline in the incidence of ionized outflows

Authors:B. Rodríguez Del Pino, S. Arribas, A. L. Chies-Santos, I. Lamperti, M. Perna, J. M. Vílchez

Abstract: AGN have been generally considered to be less frequent in denser environments due to the lower number of galaxy-galaxy interactions and/or the removal of their gas-rich reservoirs by the dense intergalactic medium. However, recent observational and theoretical works suggest that the effect of ram-pressure stripping might reduce the angular momentum of their gas, causing it to infall towards the super massive black hole (SMBH) at their centre, activating the AGN phase. In this work we explore the connection between environment and nuclear activity by evaluating the variation in the incidence of ionized outflows in AGN across different environments. We select a sample of $\sim3300$ optical AGN from the Sloan Digital Sky Survey Data Release 13 that we match with the group catalogue from Lim et al. 2017. We further probe their environment through the projected distance to the central galaxy of the group/cluster and the projected surface density to the 5th neighbour ($\delta_5$). We find that at lower masses ($<10^{10.3}$M$_{\odot}$), the fraction of ionized outflows is significantly lower in satellite ($\sim7$%) than in isolated ($\sim22$%) AGN. The fraction of outflows in all satellite AGN decreases towards closer distances to the central, whereas only the lower-mass ones display a significant decline with $\delta_5$. Although this study does not include AGN in the densest regions of galaxy clusters, our findings suggest that AGN in dense environments accrete less gas than those in the field potentially due to the removal of the gas reservoirs via stripping or starvation, consistent with a negative connection between environment and AGN activity. We propose that the observed change in the incidence of outflows towards denser regions of groups and clusters could contribute to the higher gas metallicities of cluster galaxies compared to field ones, especially at lower masses.

8.MUSEQuBES: The relation between Ly$α$ emitters and C IV absorbers at $z \approx 3.3$

Authors:Eshita Banerjee, Sowgat Muzahid, Joop Schaye, Sean D. Johnson, Sebastiano Cantalupo

Abstract: We present a detailed study of the column density and covering fraction profiles of C IV absorption around 86 redshift $z \approx 3.3$ Ly$\alpha$ emitters (LAEs) detected in 8 Multi-Unit Spectroscopic Explorer (MUSE) fields of $1'\times 1'$ centered on 8 bright background quasars as part of the MUSEQuBES survey. Using Voigt profile fitting of all the C IV absorbers detected along these 8 sightlines, we generated a ``blind'' absorbers' catalog consisting of 489 C IV absorption components. We cross-matched this blind C IV catalog with the MUSE-detected LAE catalog and found a significant enhancement of C IV components within $\approx \pm$400 $\rm km\, s^{-1}$ of the systemic redshifts of the LAEs. Neither the C IV column density ($N$) nor the Doppler parameter ($b$) of individual C IV components shows any significant anti-correlation with impact parameter ($\rho$) of the LAEs in the 68 percentile range of $90\leq \rho \leq 230$ physical kpc (pkpc). We find a covering fraction of $\approx 60\%$ for a threshold $N$(C IV) of $10^{12.5}\, \rm \rm cm^{-2}$, which is roughly twice as high as in random regions. The C IV covering fraction remains constant at $\approx50\%$ for impact parameters in the range 150--250~pkpc ($\approx 3-6 R_{200}$). Using the covering fraction profile, we constrained the LAE--C IV absorber two-point correlation function, and obtained $r_0 = 3.2~h^{-1}$ comoving Mpc (cMpc) and $\gamma = 1.2$ for a threshold $N$(C IV) of $10^{13.0}\, \rm cm^{-2}$. The C IV covering fraction is found to be enhanced for the LAEs that are part of a ``pair/group'' compared to the isolated ones.

9.Simulated observations of star formation regions: infrared evolution of globally collapsing clouds

Authors:Jesús M. Jáquez-Domínguez Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Roberto Galván-Madrid Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Jacopo Fritz Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Manuel Zamora-Avilés Instituto Nacional de Astrofísica, Óptica y Electrónica, Peter Camps Sterrenkundig Observatorium, Universiteit Gent, Gustavo Bruzual Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Maarten Baes Sterrenkundig Observatorium, Universiteit Gent, Yuxin Lin Max Planck Institute for extraterrestrial Physics, Enrique Vázquez-Semadeni Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México

Abstract: The direct comparison between hydrodynamical simulations and observations is needed to improve the physics included in the former and test biases in the latter. Post-processing radiative transfer and synthetic observations are now the standard way to do this. We report on the first application of the \texttt{SKIRT} radiative transfer code to simulations of a star-forming cloud. The synthetic observations are then analyzed following traditional observational workflows. We find that in the early stages of the simulation, stellar radiation is inefficient in heating dust to the temperatures observed in Galactic clouds, thus the addition of an interstellar radiation field is necessary. The spectral energy distribution of the cloud settles rather quickly after $\sim3$ Myr of evolution from the onset of star formation, but its morphology continues to evolve for $\sim8$ Myr due to the expansion of \textsc{Hii} regions and the respective creation of cavities, filaments, and ridges. Modeling synthetic \textit{Herschel} fluxes with 1- or 2-component modified black bodies underestimates total dust masses by a factor of $\sim2$. Spatially-resolved fitting recovers up to about $70\%$ of the intrinsic value. This ``missing mass'' is located in a very cold dust component with temperatures below $10$ K, which does not contribute appreciably to the far-infrared flux. This effect could bias real observations if such dust exists in large amounts. Finally, we tested observational calibrations of the SFR based on infrared fluxes and concluded that they are in agreement when compared to the intrinsic SFR of the simulation averaged over $\sim100$ Myr.