High Energy Astrophysical Phenomena (astro-ph.HE)
Tue, 09 May 2023
1.Multi-messenger observations of double neutron stars in Galactic disk with gravitational and radio waves
Authors:Wen-Fan Feng, Jie-Wen Chen, Yan Wang, Soumya D. Mohanty, Yong Shao
Abstract: We evaluate the prospects for radio follow-up of the double neutron stars (DNSs) in the Galactic disk that could be detected through future space-borne gravitational wave (GW) detectors. We first simulate the DNS population in the Galactic disk that is accessible to space-borne GW detectors according to the merger rate from recent LIGO results. Using the inspiraling waveform for the eccentric binary, the average number of the DNSs detectable by TianQin (TQ), LISA, and TQ+LISA are 217, 368, and 429, respectively. For the joint GW detection of TQ+LISA, the forecasted parameter estimation accuracies, based on the Fisher information matrix, for the detectable sources can reach the levels of $\Delta P_{\mathrm b}/P_{\mathrm b} \lesssim 10^{-6}$, $\Delta \Omega \lesssim 100~{\mathrm {deg}}^2$, $\Delta e/e \lesssim 0.3$, and $\Delta \dot{P}_{\mathrm b} / \dot{P}_{\mathrm b} \lesssim 0.02$. These estimation accuracies are fitted in the form of power-law function of signal-to-noise ratio. Next, we simulate the radio pulse emission from the possible pulsars in these DNSs according to pulsar beam geometry and the empirical distributions of spin period and luminosity. For the DNSs detectable by TQ+LISA, the average number of DNSs detectable by the follow-up pulsar searches using the Parkes, FAST, SKA1, and SKA are 8, 10, 43, and 87, respectively. Depending on the radio telescope, the average distances of these GW-detectable pulsar binaries vary from 1 to 7 kpc. Considering the dominant radiometer noise and phase jitter noise, the timing accuracy of these GW-detectable pulsars can be as low as 70 ${\rm ns}$ while the most probable value is about 100 $\mu {\rm s}$.
2.A renewed search for radio emission from the variable $γ$-ray pulsar PSR J2021$+$4026
Authors:B. Shaw, B. W. Stappers, P. Weltevrede, C. A. Jordan, M. B. Mickaliger A. G. Lyne
Abstract: We undertake the first targeted search at 1.5 GHz for radio emission from the variable $\gamma$-ray pulsar PSR J2021$+$4026. This radio-quiet pulsar assumes one of two stable $\gamma$-ray emission states, between which it transitions on a timescale of years. These transitions, in both $\gamma$-ray flux and pulse profile shape, are accompanied by contemporaneous changes to the pulsar's spin-down rate. A number of radio pulsars are known to exhibit similar correlated variability, which in some cases involves an emission state in which the radio emission ceases to be detectable. In this paper, we perform a search for radio emission from PSR J2021$+$4026, using archival radio observations recorded when the pulsar was in each of its emission/spin-down states. Using improved techniques, we search for periodic radio emission as well as single pulse phenomena such as giant radio pulses and RRAT-like emission. Our search reveals no evidence of radio emission from PSR J2021$+$4026. We estimate that the flux density for periodic emission from PSR J2021$+$4026 does not exceed 0.2 mJy at this frequency. We also estimate single-pulse flux limits for RRAT-like bursts and giant radio pulses to be 0.3 and 100 Jy respectively. We discuss the transitioning behaviour of PSR J2021$+$4026 in the context of pulsar glitches, intermittent pulsars and the increasingly common emission-rotation correlation observed in radio pulsars.
3.Shocks Power Tidal Disruption Events
Authors:Taeho Ryu, Julian Krolik, Tsvi Piran, Scott Noble, Mark Avara
Abstract: Accretion of debris seems to be the natural mechanism to power the radiation emitted during a tidal disruption event (TDE), in which a supermassive black hole tears apart a star. However, this requires the prompt formation of a compact accretion disk. Here, using a fully relativistic global simulation for the long-term evolution of debris in a TDE with realistic initial conditions, we show that at most a tiny fraction of the bound mass enters such a disk on the timescale of observed flares. To "circularize" most of the bound mass entails an increase in the binding energy of that mass by a factor $\sim 30$; we find at most an order unity change. Our simulation suggests it would take a time scale comparable to a few tens of the characteristic mass fallback time to dissipate enough energy for "circularization". Instead, the bound debris forms an extended eccentric accretion flow with eccentricity $\simeq 0.4-0.5$ by $\sim 2$ fallback times. Although the energy dissipated in shocks in this large-scale flow is much smaller than the "circularization" energy, it matches the observed radiated energy very well. Nonetheless, the impact of shocks is not strong enough to unbind initially bound debris into an outflow.
4.Measurement of ultra-high-energy diffuse gamma-ray emission of the Galactic plane from 10 TeV to 1 PeV with LHAASO-KM2A
Authors:Zhen Cao The LHAASO Collaboration, F. Aharonian The LHAASO Collaboration, Q. An The LHAASO Collaboration, Axikegu The LHAASO Collaboration, Y. X. Bai The LHAASO Collaboration, Y. W. Bao The LHAASO Collaboration, D. Bastieri The LHAASO Collaboration, X. J. Bi The LHAASO Collaboration, Y. J. Bi The LHAASO Collaboration, J. T. Cai The LHAASO Collaboration, Q. Cao The LHAASO Collaboration, W. Y. Cao The LHAASO Collaboration, Zhe Cao The LHAASO Collaboration, J. Chang The LHAASO Collaboration, J. F. Chang The LHAASO Collaboration, A. M. Chen The LHAASO Collaboration, E. S. Chen The LHAASO Collaboration, Liang Chen The LHAASO Collaboration, Lin Chen The LHAASO Collaboration, Long Chen The LHAASO Collaboration, M. J. Chen The LHAASO Collaboration, M. L. Chen The LHAASO Collaboration, Q. H. Chen The LHAASO Collaboration, S. H. Chen The LHAASO Collaboration, S. Z. Chen The LHAASO Collaboration, T. L. Chen The LHAASO Collaboration, Y. Chen The LHAASO Collaboration, N. Cheng The LHAASO Collaboration, Y. D. Cheng The LHAASO Collaboration, M. Y. Cui The LHAASO Collaboration, S. W. Cui The LHAASO Collaboration, X. H. Cui The LHAASO Collaboration, Y. D. Cui The LHAASO Collaboration, B. Z. Dai The LHAASO Collaboration, H. L. Dai The LHAASO Collaboration, Z. G. Dai The LHAASO Collaboration, Danzengluobu The LHAASO Collaboration, D. della Volpe The LHAASO Collaboration, X. Q. Dong The LHAASO Collaboration, K. K. Duan The LHAASO Collaboration, J. H. Fan The LHAASO Collaboration, Y. Z. Fan The LHAASO Collaboration, J. Fang The LHAASO Collaboration, K. Fang The LHAASO Collaboration, C. F. Feng The LHAASO Collaboration, L. Feng The LHAASO Collaboration, S. H. Feng The LHAASO Collaboration, X. T. Feng The LHAASO Collaboration, Y. L. Feng The LHAASO Collaboration, S. Gabici The LHAASO Collaboration, B. Gao The LHAASO Collaboration, C. D. Gao The LHAASO Collaboration, L. Q. Gao The LHAASO Collaboration, Q. Gao The LHAASO Collaboration, W. Gao The LHAASO Collaboration, W. K. Gao The LHAASO Collaboration, M. M. Ge The LHAASO Collaboration, L. S. Geng The LHAASO Collaboration, G. Giacinti The LHAASO Collaboration, G. H. Gong The LHAASO Collaboration, Q. B. Gou The LHAASO Collaboration, M. H. Gu The LHAASO Collaboration, F. L. Guo The LHAASO Collaboration, X. L. Guo The LHAASO Collaboration, Y. Q. Guo The LHAASO Collaboration, Y. Y. Guo The LHAASO Collaboration, Y. A. Han The LHAASO Collaboration, H. H. He The LHAASO Collaboration, H. N. He The LHAASO Collaboration, J. Y. He The LHAASO Collaboration, X. B. He The LHAASO Collaboration, Y. He The LHAASO Collaboration, M. Heller The LHAASO Collaboration, Y. K. Hor The LHAASO Collaboration, B. W. Hou The LHAASO Collaboration, C. Hou The LHAASO Collaboration, X. Hou The LHAASO Collaboration, H. B. Hu The LHAASO Collaboration, Q. Hu The LHAASO Collaboration, S. C. Hu The LHAASO Collaboration, D. H. Huang The LHAASO Collaboration, T. Q. Huang The LHAASO Collaboration, W. J. Huang The LHAASO Collaboration, X. T. Huang The LHAASO Collaboration, X. Y. Huang The LHAASO Collaboration, Y. Huang The LHAASO Collaboration, Z. C. Huang The LHAASO Collaboration, X. L. Ji The LHAASO Collaboration, H. Y. Jia The LHAASO Collaboration, K. Jia The LHAASO Collaboration, K. Jiang The LHAASO Collaboration, X. W. Jiang The LHAASO Collaboration, Z. J. Jiang The LHAASO Collaboration, M. Jin The LHAASO Collaboration, M. M. Kang The LHAASO Collaboration, T. Ke The LHAASO Collaboration, D. Kuleshov The LHAASO Collaboration, K. Kurinov The LHAASO Collaboration, B. B. Li The LHAASO Collaboration, Cheng Li The LHAASO Collaboration, Cong Li The LHAASO Collaboration, D. Li The LHAASO Collaboration, F. Li The LHAASO Collaboration, H. B. Li The LHAASO Collaboration, H. C. Li The LHAASO Collaboration, H. Y. Li The LHAASO Collaboration, J. Li The LHAASO Collaboration, Jian Li The LHAASO Collaboration, Jie Li The LHAASO Collaboration, K. Li The LHAASO Collaboration, W. L. Li The LHAASO Collaboration, W. L. Li The LHAASO Collaboration, X. R. Li The LHAASO Collaboration, Xin Li The LHAASO Collaboration, Y. Z. Li The LHAASO Collaboration, Zhe Li The LHAASO Collaboration, Zhuo Li The LHAASO Collaboration, E. W. Liang The LHAASO Collaboration, Y. F. Liang The LHAASO Collaboration, S. J. Lin The LHAASO Collaboration, B. Liu The LHAASO Collaboration, C. Liu The LHAASO Collaboration, D. Liu The LHAASO Collaboration, H. Liu The LHAASO Collaboration, H. D. Liu The LHAASO Collaboration, J. Liu The LHAASO Collaboration, J. L. Liu The LHAASO Collaboration, J. Y. Liu The LHAASO Collaboration, M. Y. Liu The LHAASO Collaboration, R. Y. Liu The LHAASO Collaboration, S. M. Liu The LHAASO Collaboration, W. Liu The LHAASO Collaboration, Y. Liu The LHAASO Collaboration, Y. N. Liu The LHAASO Collaboration, R. Lu The LHAASO Collaboration, Q. Luo The LHAASO Collaboration, H. K. Lv The LHAASO Collaboration, B. Q. Ma The LHAASO Collaboration, L. L. Ma The LHAASO Collaboration, X. H. Ma The LHAASO Collaboration, J. R. Mao The LHAASO Collaboration, Z. Min The LHAASO Collaboration, W. Mitthumsiri The LHAASO Collaboration, H. J. Mu The LHAASO Collaboration, Y. C. Nan The LHAASO Collaboration, A. Neronov The LHAASO Collaboration, Z. W. Ou The LHAASO Collaboration, B. Y. Pang The LHAASO Collaboration, P. Pattarakijwanich The LHAASO Collaboration, Z. Y. Pei The LHAASO Collaboration, M. Y. Qi The LHAASO Collaboration, Y. Q. Qi The LHAASO Collaboration, B. Q. Qiao The LHAASO Collaboration, J. J. Qin The LHAASO Collaboration, D. Ruffolo The LHAASO Collaboration, A. Saiz The LHAASO Collaboration, D. Semikoz The LHAASO Collaboration, C. Y. Shao The LHAASO Collaboration, L. Shao The LHAASO Collaboration, O. Shchegolev The LHAASO Collaboration, X. D. Sheng The LHAASO Collaboration, F. W. Shu The LHAASO Collaboration, H. C. Song The LHAASO Collaboration, Yu. V. Stenkin The LHAASO Collaboration, V. Stepanov The LHAASO Collaboration, Y. Su The LHAASO Collaboration, Q. N. Sun The LHAASO Collaboration, X. N. Sun The LHAASO Collaboration, Z. B. Sun The LHAASO Collaboration, P. H. T. Tam The LHAASO Collaboration, Q. W. Tang The LHAASO Collaboration, Z. B. Tang The LHAASO Collaboration, W. W. Tian The LHAASO Collaboration, C. Wang The LHAASO Collaboration, C. B. Wang The LHAASO Collaboration, G. W. Wang The LHAASO Collaboration, H. G. Wang The LHAASO Collaboration, H. H. Wang The LHAASO Collaboration, J. C. Wang The LHAASO Collaboration, K. Wang The LHAASO Collaboration, L. P. Wang The LHAASO Collaboration, L. Y. Wang The LHAASO Collaboration, P. H. Wang The LHAASO Collaboration, R. Wang The LHAASO Collaboration, W. Wang The LHAASO Collaboration, X. G. Wang The LHAASO Collaboration, X. Y. Wang The LHAASO Collaboration, Y. Wang The LHAASO Collaboration, Y. D. Wang The LHAASO Collaboration, Y. J. Wang The LHAASO Collaboration, Z. H. Wang The LHAASO Collaboration, Z. X. Wang The LHAASO Collaboration, Zhen Wang The LHAASO Collaboration, Zheng Wang The LHAASO Collaboration, D. M. Wei The LHAASO Collaboration, J. J. Wei The LHAASO Collaboration, Y. J. Wei The LHAASO Collaboration, T. Wen The LHAASO Collaboration, C. Y. Wu The LHAASO Collaboration, H. R. Wu The LHAASO Collaboration, S. Wu The LHAASO Collaboration, X. F. Wu The LHAASO Collaboration, Y. S. Wu The LHAASO Collaboration, S. Q. Xi The LHAASO Collaboration, J. Xia The LHAASO Collaboration, J. J. Xia The LHAASO Collaboration, G. M. Xiang The LHAASO Collaboration, D. X. Xiao The LHAASO Collaboration, G. Xiao The LHAASO Collaboration, G. G. Xin The LHAASO Collaboration, Y. L. Xin The LHAASO Collaboration, Y. Xing The LHAASO Collaboration, Z. Xiong The LHAASO Collaboration, D. L. Xu The LHAASO Collaboration, R. F. Xu The LHAASO Collaboration, R. X. Xu The LHAASO Collaboration, W. L. Xu The LHAASO Collaboration, L. Xue The LHAASO Collaboration, D. H. Yan The LHAASO Collaboration, J. Z. Yan The LHAASO Collaboration, T. Yan The LHAASO Collaboration, C. W. Yang The LHAASO Collaboration, F. Yang The LHAASO Collaboration, F. F. Yang The LHAASO Collaboration, H. W. Yang The LHAASO Collaboration, J. Y. Yang The LHAASO Collaboration, L. L. Yang The LHAASO Collaboration, M. J. Yang The LHAASO Collaboration, R. Z. Yang The LHAASO Collaboration, S. B. Yang The LHAASO Collaboration, Y. H. Yao The LHAASO Collaboration, Z. G. Yao The LHAASO Collaboration, Y. M. Ye The LHAASO Collaboration, L. Q. Yin The LHAASO Collaboration, N. Yin The LHAASO Collaboration, X. H. You The LHAASO Collaboration, Z. Y. You The LHAASO Collaboration, Y. H. Yu The LHAASO Collaboration, Q. Yuan The LHAASO Collaboration, H. Yue The LHAASO Collaboration, H. D. Zeng The LHAASO Collaboration, T. X. Zeng The LHAASO Collaboration, W. Zeng The LHAASO Collaboration, M. Zha The LHAASO Collaboration, B. B. Zhang The LHAASO Collaboration, F. Zhang The LHAASO Collaboration, H. M. Zhang The LHAASO Collaboration, H. Y. Zhang The LHAASO Collaboration, J. L. Zhang The LHAASO Collaboration, L. X. Zhang The LHAASO Collaboration, Li Zhang The LHAASO Collaboration, P. F. Zhang The LHAASO Collaboration, P. P. Zhang The LHAASO Collaboration, R. Zhang The LHAASO Collaboration, S. B. Zhang The LHAASO Collaboration, S. R. Zhang The LHAASO Collaboration, S. S. Zhang The LHAASO Collaboration, X. Zhang The LHAASO Collaboration, X. P. Zhang The LHAASO Collaboration, Y. F. Zhang The LHAASO Collaboration, Yi Zhang The LHAASO Collaboration, Yong Zhang The LHAASO Collaboration, B. Zhao The LHAASO Collaboration, J. Zhao The LHAASO Collaboration, L. Zhao The LHAASO Collaboration, L. Z. Zhao The LHAASO Collaboration, S. P. Zhao The LHAASO Collaboration, F. Zheng The LHAASO Collaboration, B. Zhou The LHAASO Collaboration, H. Zhou The LHAASO Collaboration, J. N. Zhou The LHAASO Collaboration, M. Zhou The LHAASO Collaboration, P. Zhou The LHAASO Collaboration, R. Zhou The LHAASO Collaboration, X. X. Zhou The LHAASO Collaboration, C. G. Zhu The LHAASO Collaboration, F. R. Zhu The LHAASO Collaboration, H. Zhu The LHAASO Collaboration, K. J. Zhu The LHAASO Collaboration, X. Zuo The LHAASO Collaboration
Abstract: The diffuse Galactic $\gamma$-ray emission, mainly produced via interactions between cosmic rays and the diffuse interstellar medium, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this work we report the measurements of diffuse $\gamma$-rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner ($15^{\circ}<l<125^{\circ}$, $|b|<5^{\circ}$) and outer ($125^{\circ}<l<235^{\circ}$, $|b|<5^{\circ}$) Galactic plane are detected with $29.1\sigma$ and $12.7\sigma$ significance, respectively. The outer Galactic plane diffuse emission is detected for the first time in the very- to ultra-high-energy domain ($E>10$~TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of $-2.99\pm0.04$, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of $\sim3$ than the prediction. A similar spectrum with an index of $-2.99\pm0.07$ is found in the outer Galaxy region, and the absolute flux for $10\lesssim E\lesssim60$ TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show slight deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.
5.R-modes as a New Probe of Dark Matter in Neutron Stars
Authors:Swarnim Shirke, Suprovo Ghosh, Debarati Chatterjee, Laura Sagunski, Jürgen Schaffner-Bielich
Abstract: In this work, we perform the first systematic investigation of effects of the presence of dark matter on r-mode oscillations in neutron stars (NSs). Using a self-interacting dark matter (DM) model based on the neutron decay anomaly and a hadronic model obtained from the posterior distribution of a recent Bayesian analysis, we impose constraints on the DM self-interaction strength using recent multimessenger astrophysical observations. The constrained DM interaction strength is then used to estimate DM self-interaction cross section and shear viscosity resulting from DM, which is found to be several orders of magnitude smaller than shear viscosity due to hadronic matter. Assuming that the DM fermion is in chemical equilibrium with the neutrons in the neutron star, we estimate the bulk viscosity resulting from the dark decay of neutrons, and find it to be much smaller than the hadronic bulk viscosity. We also conclude that the instability window with minimal hadronic damping mechanisms can become smaller when including DM shear and bulk viscosity but remains incompatible with the X-ray and pulsar observational data for the chosen DM model.