High Energy Astrophysical Phenomena (astro-ph.HE)
Mon, 07 Aug 2023
1.Energy-resolved pulse profiles of accreting pulsars: Diagnostic tools for spectral features
Authors:Carlo Ferrigno, Antonino D'Aì, Elena Ambrosi
Abstract: We introduce a method for extracting spectral information from energy-resolved light curves folded at the neutron star spin period (known as pulse profiles) in accreting X-ray binaries. Spectra of these sources are sometimes characterized by features superimposed on a smooth continuum, such as iron emission lines and cyclotron resonant scattering features. We address here the question on how to derive quantitative constraints on such features from energy-dependent changes in the pulse profiles. We developed a robust method for determining in each energy-selected bin the value of the pulsed fraction using the fast Fourier transform opportunely truncated at the number of harmonics needed to satisfactorily describe the actual profile. We determined the uncertainty on this value by sampling through Monte Carlo simulations a total of 1000 faked profiles. We rebinned the energy-resolved pulse profiles to have a constant minimum signal-to-noise ratio throughout the whole energy band. Finally we characterize the dependence of the energy-resolved pulsed fraction using a phenomenological polynomial model and search for features corresponding to spectral signatures of iron emission or cyclotron lines using Gaussian line profiles. We apply our method to a representative sample of NuSTAR observations of well-known accreting X-ray pulsars. We show that, with this method, it is possible to characterize the pulsed fraction spectra, and to constrain the position and widths of such features with a precision comparable with the spectral results. We also explore how harmonic decomposition, correlation, and lag spectra might be used as additional probes for detection and characterization of such features.
2.Bayesian inference from gravitational waves in fast-rotating, core-collapse supernovae
Authors:Carlos Pastor-Marcos, Pablo Cerdá-Durán, Daniel Walker, Alejandro Torres-Forné, Ernazar Abdikamalov, Sherwood Richers, José Antonio Font
Abstract: Core-collapse supernovae (CCSNe) are prime candidates for gravitational-wave detectors. The analysis of their complex waveforms can potentially provide information on the physical processes operating during the collapse of the iron cores of massive stars. In this work we analyze the early-bounce rapidly rotating CCSN signals reported in the waveform catalog of Richers et al 2017, which comprises over 1800 axisymmetric simulations extending up to about $10$~ms of post-bounce evolution. It was previously established that for a large range of progenitors, the amplitude of the bounce signal, $\Delta h$, is proportional to the ratio of rotational-kinetic energy to potential energy, T/|W|, and the peak frequency, $f_{\rm peak}$, is proportional to the square root of the central rest-mass density. In this work, we exploit these relations to suggest that it could be possible to use such waveforms to infer protoneutron star properties from a future gravitational wave observation, if the distance and inclination are well known. Our approach relies on the ability to describe a subset of the waveforms in the early post-bounce phase in a simple template form depending only on two parameters, $\Delta h$ and $f_{\rm peak}$. We use this template to perform a Bayesian inference analysis of waveform injections in Gaussian colored noise for a network of three gravitational wave detectors formed by Advanced LIGO and Advanced Virgo. We show that it is possible to recover the injected parameters, peak frequency and amplitude, with an accuracy better than 10% for more than 50% of the detectable signals (given known distance and inclination angle). However, inference on waveforms from outside the Richers catalog is not reliable, indicating a need for carefully verified waveforms of the first 10 ms after bounce of rapidly rotating supernovae of different progenitors with agreement between different codes.
3.A catalogue of unusually long thermonuclear bursts on neutron stars
Authors:Khaled Alizai, Jérôme Chenevez, Andrew Cumming, Nathalie Degenaar, Maurizio Falanga, Duncan K. Galloway, Jean J. M. in `t Zand, Gaurava K. Jaisawal, Laurens Keek, Erik Kuulkers, Nathanael Lampe, Hendrik Schatz, Motoko Serino
Abstract: Rare, energetic (long) thermonuclear (Type I) X-ray bursts are classified either as intermediate-duration or superbursts, based on their duration. Intermediate-duration bursts lasting a few to tens of minutes are thought to arise from the thermonuclear runaway of a relatively thick (10^10 g/cm2) helium layer, while superbursts lasting hours are attributed to the detonation of an underlying carbon layer. We present a catalogue of 84 long thermonuclear bursts from 40 low-mass X-ray binaries, and defined from a new set of criteria distinguishing them from the more frequent short bursts. The three criteria are: (1) a total energy release larger than 10^40 erg, (2) a photospheric radius expansion phase longer than 10 s, and (3) a burst time-scale longer than 70 s. This work is based on a comprehensive systematic analysis of 70 bursts found with INTEGRAL, RXTE, Swift, BeppoSAX, MAXI, and NICER, as well as 14 long bursts from the literature that were detected with earlier generations of X-ray instruments. For each burst, we measure its peak flux and fluence, which eventually allows us to confirm the distinction between intermediate-duration bursts and superbursts. Additionally, we list 18 bursts that only partially meet the above inclusion criteria, possibly bridging the gap between normal and intermediate-duration bursts. With this catalogue, we significantly increase the number of long-duration bursts included in the MINBAR and thereby provide a substantial sample of these rare X-ray bursts for further study.
4.A re-emerging bright soft-X-ray state of the changing-look Active Galactic Nucleus 1ES~1927+654: a multi-wavelength view
Authors:Ritesh Ghosh, Sibasish Laha, Eileen Meyer, Agniva Roychowdhury, Xiaolong Yang, J. A. Acosta Pulido, Suvendu Rakshit, Shivangi Pandey, Josefa Becerra Gonzalez, Ehud Behar, Luigi C. Gallo, Francesca Panessa, Stefano Bianchi, Fabio La Franca, Nicolas Scepi, Mitchell C. Begelman, Anna Lia Longinotti, Elisabeta Lusso, Samantha Oates, Matt Nicholl, S. Bradley Cenko, Brendan O Connor, Erica Hammerstein, Jincen Jose, Krisztina Eva Gabanyi, Federica Ricci, Sabyasachi Chattopadhyay
Abstract: 1ES1927+654 is a nearby active galactic nucleus that has shown an enigmatic outburst in optical/UV followed by X-rays, exhibiting strange variability patterns at timescales of months-years. Here we report the unusual X-ray, UV, and radio variability of the source in its post-flare state (Jan 2022- May 2023). Firstly, we detect an increase in the soft X-ray (0.3-2 keV) flux from May 2022- May 2023 by almost a factor of five, which we call the bright-soft-state. The hard X-ray 2-10 keV flux increased by a factor of two, while the UV flux density did not show any significant changes ($\le 30\%$) in the same period. The integrated energy pumped into the soft and hard X-ray during this period of eleven months is $\sim 3.57\times 10^{50}$ erg and $5.9\times 10^{49}$ erg, respectively. From the energetics, it is evident that whatever is producing the soft excess (SE) is pumping out more energy than either the UV or hard X-ray source. Since the energy source presumably is ultimately the accretion of matter onto the SMBH, the SE emitting region must be receiving the majority of this energy. In addition, the source does not follow the typical disc-corona relation found in AGNs, neither in the initial flare (in 2017-2019) nor in the current bright soft state (2022-2023). We found that the core (<1 pc) radio emission at 5 GHz gradually increased till March 2022 but showed a dip in August 2022. The G\"udel Benz relation ($L_{\rm radio}/L_{\rm X-ray}\sim 10^{-5}$), however, is still within the expected range for radio-quiet AGN and further follow-up radio observations are currently being undertaken.
5.Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo
Authors:The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, A. G. Abac, R. Abbott, H. Abe, F. Acernese, K. Ackley, C. Adamcewicz, S. Adhicary, N. Adhikari, R. X. Adhikari, V. K. Adkins, V. B. Adya, C. Affeldt, D. Agarwal, M. Agathos, O. D. Aguiar, I. Aguilar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, S. Albanesi, R. A. Alfaidi, A. Al-Jodah, C. Alléné, A. Allocca, M. Almualla, P. A. Altin, S. Álvarez-López, A. Amato, L. Amez-Droz, A. Amorosi, S. Anand, A. Ananyeva, R. Andersen, S. B. Anderson, W. G. Anderson, M. Andia, M. Ando, T. Andrade, N. Andres, M. Andrés-Carcasona, T. Andrić, S. Ansoldi, J. M. Antelis, S. Antier, M. Aoumi, T. Apostolatos, E. Z. Appavuravther, S. Appert, S. K. Apple, K. Arai, A. Araya, M. C. Araya, J. S. Areeda, N. Aritomi, F. Armato, N. Arnaud, M. Arogeti, S. M. Aronson, K. G. Arun, G. Ashton, Y. Aso, M. Assiduo, S. Assis de Souza Melo, S. M. Aston, P. Astone, F. Aubin, K. AultONeal, S. Babak, A. Badalyan, F. Badaracco, C. Badger, S. Bae, S. Bagnasco, Y. Bai, J. G. Baier, R. Bajpai, T. Baka, M. Ball, G. Ballardin, S. W. Ballmer, G. Baltus, S. Banagiri, B. Banerjee, D. Bankar, P. Baral, J. C. Barayoga, J. Barber, B. C. Barish, D. Barker, P. Barneo, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, S. D. Barthelmy, M. A. Barton, I. Bartos, S. Basak, A. Basalaev, R. Bassiri, A. Basti, M. Bawaj, P. Baxi, J. C. Bayley, A. C. Baylor, M. Bazzan, B. Bécsy, V. M. Bedakihale, F. Beirnaert, M. Bejger, A. S. Bell, V. Benedetto, D. Beniwal, W. Benoit, J. D. Bentley, M. Ben Yaala, S. Bera, M. Berbel, F. Bergamin, B. K. Berger, S. Bernuzzi, M. Beroiz, C. P. L. Berry, D. Bersanetti, A. Bertolini, J. Betzwieser, D. Beveridge, N. Bevins, R. Bhandare, A. V. Bhandari, U. Bhardwaj, R. Bhatt, D. Bhattacharjee, S. Bhaumik, A. Bianchi, I. A. Bilenko, M. Bilicki, G. Billingsley, A. Binetti, S. Bini, O. Birnholtz, S. Biscans, M. Bischi, S. Biscoveanu, A. Bisht, M. Bitossi, M. -A. Bizouard, J. K. Blackburn, C. D. Blair, D. G. Blair, F. Bobba, N. Bode, M. Boër, G. Bogaert, G. Boileau, M. Boldrini, G. N. Bolingbroke, L. D. Bonavena, R. Bondarescu, F. Bondu, E. Bonilla, M. S. Bonilla, R. Bonnand, P. Booker, V. Boschi, S. Bose, V. Bossilkov, V. Boudart, A. Bozzi, C. Bradaschia, P. R. Brady, M. Braglia, A. Branch, M. Branchesi, M. Breschi, T. Briant, A. Brillet, M. Brinkmann, P. Brockill, A. F. Brooks, D. D. Brown, M. L. Brozzetti, S. Brunett, G. Bruno, R. Bruntz, J. Bryant, F. Bucci, J. Buchanan, O. Bulashenko, T. Bulik, H. J. Bulten, A. Buonanno, K. Burtnyk, R. Buscicchio, D. Buskulic, C. Buy, G. S. Cabourn Davies, G. Cabras, R. Cabrita, L. Cadonati, G. Cagnoli, C. Cahillane, H. W. Cain III, J. Calderón Bustillo, J. D. Callaghan, T. A. Callister, E. Calloni, J. B. Camp, M. Canepa, G. Caneva Santoro, M. Cannavacciuolo, K. C. Cannon, H. Cao, Z. Cao, L. A. Capistran, E. Capocasa, E. Capote, G. Carapella, F. Carbognani, M. Carlassara, J. B. Carlin, M. Carpinelli, J. J. Carter, G. Carullo, J. Casanueva Diaz, C. Casentini, G. Castaldi, S. Y. Castro-Lucas, S. Caudill, M. Cavaglià, R. Cavalieri, G. Cella, P. Cerdá-Durán, E. Cesarini, W. Chaibi, S. Chalathadka-Subrahmanya, C. Chan, J. C. L. Chan, K. H. M. Chan, M. Chan, W. L. Chan, K. Chandra, I. P. Chang, R. -J. Chang, W. Chang, P. Chanial, S. Chao, C. Chapman-Bird, E. L. Charlton, P. Charlton, E. Chassande-Mottin, L. Chastain, C. Chatterjee, Debarati Chatterjee, Deep Chatterjee, M. Chaturvedi, S. Chaty, K. Chatziioannou, A. Chen, A. H. -Y. Chen, D. Chen, H. Chen, H. Y. Chen, J. Chen, K. H. Chen, X. Chen, Y. -R. Chen, Y. Chen, H. Cheng, P. Chessa, H. Y. Chia, F. Chiadini, C. Chiang, G. Chiarini, A. Chiba, R. Chiba, R. Chierici, A. Chincarini, M. L. Chiofalo, A. Chiummo, C. Chou, S. Choudhary, N. Christensen, S. S. Y. Chua, K. W. Chung, G. Ciani, P. Ciecielag, M. Cieślar, M. Cifaldi, A. A. Ciobanu, R. Ciolfi, F. Clara, J. A. Clark, T. A. Clarke, P. Clearwater, S. Clesse, F. Cleva, E. Coccia, E. Codazzo, P. -F. Cohadon, M. Colleoni, C. G. Collette, J. Collins, A. Colombo, M. Colpi, C. M. Compton, L. Conti, S. J. Cooper, T. R. Corbitt, I. Cordero-Carrión, S. Corezzi, N. J. Cornish, A. Corsi, S. Cortese, C. A. Costa, R. Cottingham, M. W. Coughlin, A. Couineaux, J. -P. Coulon, S. T. Countryman, J. -F. Coupechoux, B. Cousins, P. Couvares, D. M. Coward, M. J. Cowart, B. D. Cowburn, D. C. Coyne, R. Coyne, K. Craig, J. D. E. Creighton, T. D. Creighton, A. W. Criswell, J. C. G. Crockett-Gray, M. Croquette, R. Crouch, S. G. Crowder, J. R. Cudell, T. J. Cullen, A. Cumming, E. Cuoco, M. Curyło, M. Cusinato, P. Dabadie, T. Dal Canton, S. Dall'Osso, G. Dálya, B. D'Angelo, S. Danilishin, S. D'Antonio, K. Danzmann, K. E. Darroch, C. Darsow-Fromm, L. P. Dartez, A. Dasgupta, S. Datta, V. Dattilo, A. Daumas, I. Dave, A. Davenport, M. Davier, D. Davis, M. C. Davis, E. J. Daw, M. Dax, M. Deenadayalan, J. Degallaix, M. De Laurentis, S. Deléglise, V. Del Favero, F. De Lillo, D. Dell'Aquila, W. Del Pozzo, F. De Marco, F. De Matteis, V. D'Emilio, N. Demos, T. Dent, A. Depasse, R. De Pietri, R. De Rosa, C. De Rossi, R. De Simone, S. Dhurandhar, R. Diab, P. Z. Diamond, M. C. Díaz, N. A. Didio, T. Dietrich, L. Di Fiore, C. Di Fronzo, F. Di Giovanni, M. Di Giovanni, T. Di Girolamo, D. Diksha, A. Di Lieto, A. Di Michele, J. Ding, S. Di Pace, I. Di Palma, F. Di Renzo, Divyajyoti, A. Dmitriev, Z. Doctor, E. Dohmen, P. P. Doleva, L. Donahue, L. D'Onofrio, F. Donovan, K. L. Dooley, T. Dooney, S. Doravari, O. Dorosh, M. Drago, J. C. Driggers, Y. Drori, H. Du, J. -G. Ducoin, L. Dunn, U. Dupletsa, D. D'Urso, H. Duval, P. -A. Duverne, S. E. Dwyer, C. Eassa, M. Ebersold, T. Eckhardt, G. Eddolls, B. Edelman, T. B. Edo, O. Edy, A. Effler, J. Eichholz, H. Einsle, M. Eisenmann, R. A. Eisenstein, A. Ejlli, E. Engelby, A. J. Engl, L. Errico, R. C. Essick, H. Estellés, D. Estevez, T. Etzel, C. R. Evans, M. Evans, T. M. Evans, T. Evstafyeva, B. E. Ewing, J. M. Ezquiaga, F. Fabrizi, F. Faedi, V. Fafone, H. Fair, S. Fairhurst, P. C. Fan, A. M. Farah, B. Farr, W. M. Farr, E. J. Fauchon-Jones, G. Favaro, M. Favata, M. Fays, J. Feicht, M. M. Fejer, E. Fenyvesi, D. L. Ferguson, I. Ferrante, T. A. Ferreira, F. Fidecaro, A. Fiori, I. Fiori, M. Fishbach, R. P. Fisher, R. Fittipaldi, V. Fiumara, R. Flaminio, S. M. Fleischer, L. S. Fleming, E. Floden, H. Fong, J. A. Font, B. Fornal, P. W. F. Forsyth, K. Franceschetti, A. Franke, S. Frasca, F. Frasconi, A. Frattale Mascioli, Z. Frei, A. Freise, O. Freitas, R. Frey, W. Frischhertz, P. Fritschel, V. V. Frolov, G. G. Fronzé, S. Fujii, I. Fukunaga, P. Fulda, M. Fyffe, W. E. Gabella, B. Gadre, J. R. Gair, J. Gais, S. Galaudage, S. Gallardo, R. Gamba, D. Ganapathy, A. Ganguly, S. G. Gaonkar, B. Garaventa, J. Garcia-Bellido, C. García-Núñez, C. García-Quirós, J. W. Gardner, K. A. Gardner, J. Gargiulo, F. Garufi, C. Gasbarra, B. Gateley, V. Gayathri, G. Gemme, A. Gennai, J. George, O. Gerberding, L. Gergely, N. Ghadiri, Abhirup Ghosh, Archisman Ghosh, Shaon Ghosh, Shrobana Ghosh, Suprovo Ghosh, Tathagata Ghosh, L. Giacoppo, J. A. Giaime, K. D. Giardina, D. R. Gibson, C. Gier, P. Giri, F. Gissi, S. Gkaitatzis, J. Glanzer, A. E. Gleckl, F. Glotin, J. Godfrey, P. Godwin, E. Goetz, R. Goetz, J. Golomb, S. Gomez Lopez, B. Goncharov, G. González, A. W. Goodwin-Jones, M. Gosselin, R. Gouaty, D. W. Gould, S. Goyal, B. Grace, A. Grado, V. Graham, A. E. Granados, M. Granata, V. Granata, S. Gras, P. Grassia, C. Gray, R. Gray, G. Greco, A. C. Green, S. M. Green, S. R. Green, A. M. Gretarsson, E. M. Gretarsson, D. Griffith, W. L. Griffiths, H. L. Griggs, G. Grignani, A. Grimaldi, C. Grimaud, H. Grote, A. S. Gruson, D. Guerra, D. Guetta, G. M. Guidi, A. R. Guimaraes, H. K. Gulati, F. Gulminelli, A. M. Gunny, H. Guo, Y. Guo, Anchal Gupta, Anuradha Gupta, Ish Gupta, N. C. Gupta, P. Gupta, S. K. Gupta, N. Gupte, R. Gurav, J. Gurs, E. K. Gustafson, N. Gutierrez, F. Guzman, D. Haba, L. Haegel, G. Hain, S. Haino, O. Halim, E. D. Hall, E. Z. Hamilton, G. Hammond, W. -B. Han, M. Haney, J. Hanks, C. Hanna, M. D. Hannam, O. A. Hannuksela, A. G. Hanselman, H. Hansen, J. Hanson, R. Harada, T. Harder, K. Haris, T. Harmark, J. Harms, G. M. Harry, I. W. Harry, D. Hartwig, B. Haskell, C. -J. Haster, J. S. Hathaway, K. Haughian, H. Hayakawa, K. Hayama, F. J. Hayes, J. Healy, A. Heffernan, A. Heidmann, M. C. Heintze, J. Heinze, J. Heinzel, H. Heitmann, F. Hellman, P. Hello, A. F. Helmling-Cornell, G. Hemming, M. Hendry, I. S. Heng, E. Hennes, J. -S. Hennig, M. Hennig, C. Henshaw, A. Hernandez, T. Hertog, M. Heurs, A. L. Hewitt, S. Higginbotham, S. Hild, P. Hill, Y. Himemoto, A. S. Hines, N. Hirata, C. Hirose, J. Ho, S. Hoang, S. Hochheim, D. Hofman, J. N. Hohmann, N. A. Holland, K. Holley-Bockelmann, I. J. Hollows, Z. J. Holmes, D. E. Holz, C. Hong, Q. Hong, J. Hornung, S. Hoshino, J. Hough, S. Hourihane, E. J. Howell, C. G. Hoy, D. Hoyland, H. -F. Hsieh, C. Hsiung, H. C. Hsu, S. -C. Hsu, W. -F. Hsu, P. Hu, Q. Hu, H. Y. Huang, Y. -J. Huang, Y. Huang, Y. T. Huang, M. T. Hübner, A. D. Huddart, B. Hughey, D. C. Y. Hui, V. Hui, R. Hur, S. Husa, R. Huxford, T. Huynh-Dinh, J. Hyland, A. Iakovlev, G. A. Iandolo, A. Iess, K. Inayoshi, Y. Inoue, G. Iorio, P. Iosif, J. Irwin, M. Isi, M. A. Ismail, Y. Itoh, M. Iwaya, B. R. Iyer, V. JaberianHamedan, T. Jacqmin, P. -E. Jacquet, S. J. Jadhav, S. P. Jadhav, D. Jain, T. Jain, A. L. James, P. A. James, R. Jamshidi, A. Z. Jan, K. Jani, L. Janiurek, J. Janquart, K. Janssens, N. N. Janthalur, S. Jaraba, P. Jaranowski, S. Jarov, P. Jasal, R. Jaume, W. Javed, K. Jenner, A. Jennings, W. Jia, J. Jiang, H. -B. Jin, K. Johansmeyer, G. R. Johns, N. A. Johnson, R. Johnston, N. Johny, D. H. Jones, D. I. Jones, R. Jones, P. Joshi, L. Ju, K. Jung, J. Junker, V. Juste, T. Kajita, C. Kalaghatgi, V. Kalogera, M. Kamiizumi, N. Kanda, S. Kandhasamy, G. Kang, J. B. Kanner, S. J. Kapadia, D. P. Kapasi, S. Karat, C. Karathanasis, S. Karki, T. Karydas, Y. A. Kas-danouche, R. Kashyap, M. Kasprzack, W. Kastaun, J. Kato, T. Kato, S. Katsanevas, E. Katsavounidis, J. K. Katsuren, W. Katzman, T. Kaur, K. Kawabe, F. Kéfélian, D. Keitel, J. Kelley-Derzon, S. A. Kemper, J. Kennington, R. Kesharwani, J. S. Key, S. Khadka, F. Y. Khalili, T. Khanam, E. A. Khazanov, M. Khursheed, N. Kijbunchoo, C. Kim, J. C. Kim, K. Kim, M. H. Kim, P. Kim, S. Kim, W. S. Kim, Y. -M. Kim, C. Kimball, N. Kimura, M. Kinley-Hanlon, R. Kirchhoff, J. S. Kissel, T. Kiyota, S. Klimenko, T. Klinger, A. M. Knee, N. Knust, P. Koch, S. M. Koehlenbeck, G. Koekoek, K. Kohri, K. Kokeyama, S. Koley, N. D. Koliadko, P. Kolitsidou, M. Kolstein, K. Komori, V. Kondrashov, A. K. H. Kong, A. Kontos, M. Korobko, R. V. Kossak, N. Kouvatsos, M. Kovalam, N. Koyama, D. B. Kozak, S. L. Kranzhoff, V. Kringel, N. V. Krishnendu, A. Królak, G. Kuehn, P. Kuijer, S. Kulkarni, A. Kulur Ramamohan, A. Kumar, Praveen Kumar, Prayush Kumar, Rahul Kumar, Rakesh Kumar, J. Kume, K. Kuns, S. Kuroyanagi, S. Kuwahara, K. Kwak, K. Kwan, G. Lacaille, P. Lagabbe, D. Laghi, S. Lai, M. H. Lakkis, E. Lalande, M. Lalleman, A. Lamberts, M. Landry, B. B. Lane, R. N. Lang, J. Lange, B. Lantz, A. La Rana, I. La Rosa, A. Lartaux-Vollard, P. D. Lasky, J. Lawrence, M. Laxen, A. Lazzarini, C. Lazzaro, P. Leaci, S. Leavey, S. LeBohec, Y. K. Lecoeuche, H. M. Lee, H. W. Lee, K. Lee, R. -K. Lee, R. Lee, S. Lee, Y. Lee, I. N. Legred, J. Lehmann, L. Lehner, A. Lemaître, M. Lenti, M. Leonardi, E. Leonova, N. Leroy, M. Lesovsky, N. Letendre, M. Lethuillier, C. Levesque, Y. Levin, K. Leyde, A. K. Y. Li, K. L. Li, T. G. F. Li, X. Li, Chien-Yu Lin, Chun-Yu Lin, E. T. Lin, F. Lin, H. Lin, L. C. -C. Lin, Y. Lin, F. Linde, S. D. Linker, T. B. Littenberg, A. Liu, G. C. Liu, Jian Liu, F. Llamas, R. K. L. Lo, T. Lo, J. -P. Locquet, L. London, A. Longo, D. Lopez, M. Lopez Portilla, M. Lorenzini, V. Loriette, M. Lormand, G. Losurdo, T. P. Lott, J. D. Lough, H. A. Loughlin, C. O. Lousto, G. Lovelace, M. J. Lowry, H. Lück, D. Lumaca, A. P. Lundgren, A. W. Lussier, J. E. Lynam, L. -T. Ma, S. Ma, M. Ma'arif, R. Macas, M. MacInnis, D. M. Macleod, I. A. O. MacMillan, A. Macquet, K. Maeda, S. Maenaut, I. Magaña Hernandez, C. Magazzù, R. M. Magee, R. Maggiore, M. Magnozzi, M. Mahesh, S. Mahesh, M. Maini, S. Majhi, E. Majorana, C. N. Makarem, S. Maliakal, A. Malik, N. Man, V. Mandic, V. Mangano, B. Mannix, G. L. Mansell, G. Mansingh, M. Manske, M. Mantovani, M. Mapelli, F. Marchesoni, D. Marín Pina, F. Marion, S. Márka, Z. Márka, C. Markakis, A. S. Markosyan, A. Markowitz, E. Maros, A. Marquina, S. Marsat, F. Martelli, I. W. Martin, R. M. Martin, B. B. Martinez, M. Martinez, V. A. Martinez, V. Martinez, A. Martini, K. Martinovic, D. V. Martynov, E. J. Marx, H. Masalehdan, A. Masserot, M. Masso-Reid, M. Mastrodicasa, S. Mastrogiovanni, M. Mateu-Lucena, M. Matiushechkina, M. Matsuyama, N. Mavalvala, N. Maxwell, G. McCarrol, R. McCarthy, D. E. McClelland, S. McCormick, L. McCuller, G. I. McGhee, J. 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Moriwaki, G. Morras, A. Moscatello, B. Mours, C. M. Mow-Lowry, S. Mozzon, F. Muciaccia, Arunava Mukherjee, D. Mukherjee, Soma Mukherjee, Subroto Mukherjee, Suvodip Mukherjee, N. Mukund, A. Mullavey, J. Munch, E. A. Muñiz, M. Murakoshi, P. G. Murray, S. Muusse, S. L. Nadji, A. Nagar, T. Nagar, N. Nagarajan, K. Nakamura, H. Nakano, M. Nakano, V. Napolano, I. Nardecchia, T. Narikawa, H. Narola, L. Naticchioni, R. K. Nayak, B. F. Neil, J. Neilson, A. Nelson, T. J. N. Nelson, M. Nery, S. Nesseris, A. Neunzert, K. Y. Ng, S. W. S. Ng, C. Nguyen, P. Nguyen, L. Nguyen Quynh, S. A. Nichols, G. Nieradka, A. Niko, Y. Nishino, A. Nishizawa, S. Nissanke, E. Nitoglia, W. Niu, F. Nocera, M. Norman, C. North, J. Novak, J. F. Nuño Siles, G. Nurbek, L. K. Nuttall, K. Obayashi, J. Oberling, J. O'Dell, E. Oelker, M. Oertel, A. Offermans, G. Oganesyan, J. J. Oh, K. Oh, S. H. Oh, T. O'Hanlon, M. Ohashi, M. Ohkawa, F. Ohme, H. Ohta, A. S. Oliveira, R. Oliveri, V. Oloworaran, B. O'Neal, K. Oohara, B. O'Reilly, R. G. Ormiston, N. D. Ormsby, M. Orselli, R. O'Shaughnessy, Y. Oshima, S. Oshino, S. Ossokine, C. Osthelder, D. J. Ottaway, A. Ouzriat, H. Overmier, A. E. Pace, R. Pagano, M. A. Page, A. Pai, S. A. Pai, A. Pal, S. Pal, O. Palashov, M. Pálfi, C. Palomba, K. -C. Pan, P. K. Panda, L. Panebianco, P. T. H. Pang, F. Pannarale, B. C. Pant, F. H. Panther, C. D. Panzer, F. Paoletti, A. Paoli, A. Paolone, E. E. Papalexakis, L. Papalini, G. Pappas, A. Parisi, J. Park, W. Parker, D. Pascucci, A. Pasqualetti, R. Passaquieti, D. Passuello, M. Patel, D. Pathak, M. Pathak, A. Patra, B. Patricelli, A. S. Patron, S. Paul, E. Payne, T. Pearce, M. Pedraza, R. Pegna, M. Pegoraro, A. Pele, F. E. Peña Arellano, S. Penn, A. Perego, A. Pereira, C. J. Perez, J. J. Perez, L. H. Perez, C. Périgois, C. C. Perkins, A. Perreca, J. Perret, S. Perriès, J. W. Perry, D. Pesios, J. Petermann, C. Petrillo, H. P. Pfeiffer, H. Pham, K. A. Pham, K. S. Phukon, H. Phurailatpam, O. J. Piccinni, M. Pichot, M. Piendibene, F. Piergiovanni, L. Pierini, G. Pierra, V. Pierro, M. . Pietrzak, G. Pillant, M. Pillas, F. Pilo, L. Pinard, C. Pineda-Bosque, I. M. Pinto, M. Pinto, B. J. Piotrzkowski, M. Pirello, M. D. Pitkin, A. Placidi, E. Placidi, M. L. Planas, W. Plastino, R. Poggiani, E. Polini, L. Pompili, S. Ponrathnam, J. Poon, E. Porcelli, J. Portell, E. K. Porter, C. Posnansky, R. Poulton, J. Powell, M. Pracchia, B. K. Pradhan, T. Pradier, A. K. Prajapati, K. Prasai, R. Prasanna, P. Prasia, G. Pratten, M. Principe, G. A. Prodi, L. Prokhorov, P. Prosposito, L. Prudenzi, A. Puecher, J. Pullin, M. Punturo, F. Puosi, P. Puppo, M. Pürrer, H. Qi, J. Qin, V. Quetschke, P. J. Quinonez, R. Quitzow-James, F. J. Raab, G. Raaijmakers, N. Radulesco, P. Raffai, S. X. Rail, S. Raja, C. Rajan, K. E. Ramirez, A. Ramos-Buades, D. Rana, E. Randel, P. R. Rangnekar, P. Rapagnani, A. Ray, V. Raymond, M. Razzano, J. Read, M. Recaman Payo, T. Regimbau, L. Rei, S. Reid, S. W. Reid, D. H. Reitze, P. Relton, A. Renzini, P. Rettegno, B. Revenu, A. Reza, M. Rezac, A. S. Rezaei, F. Ricci, M. Ricci, D. Richards, J. W. Richardson, A. Rijal, K. Riles, H. K. Riley, S. Rinaldi, C. Robertson, N. A. Robertson, F. Robinet, M. Robinson, A. Rocchi, L. Rolland, J. G. Rollins, M. Romanelli, A. E. Romano, R. Romano, A. Romero, I. M. Romero-Shaw, J. H. Romie, S. Ronchini, T. J. Roocke, L. Rosa, T. J. Rosauer, C. A. Rose, D. Rosińska, M. P. Ross, M. Rossello, S. Rowan, S. Roy, A. Royzman, D. Rozza, P. Ruggi, E. Ruiz Morales, K. Ruiz-Rocha, S. Sachdev, T. Sadecki, J. Sadiq, P. Saffarieh, S. S. Saha, T. Sainrat, S. Sajith Menon, K. Sakai, M. Sakellariadou, T. Sako, S. Sakon, O. S. Salafia, F. Salces-Carcoba, L. Salconi, M. Saleem, F. Salemi, M. Sallé, S. Salvador, A. Sanchez, E. J. Sanchez, J. H. Sanchez, L. E. Sanchez, N. Sanchis-Gual, J. R. Sanders, E. M. Sänger, T. R. Saravanan, N. Sarin, A. Sasli, P. Sassi, B. Sassolas, H. Satari, R. Sato, S. Sato, Y. Sato, O. Sauter, R. L. Savage, V. Savant, T. Sawada, H. L. Sawant, S. Sayah, D. Schaetzl, M. Scheel, S. J. Scherf, J. Scheuer, M. G. Schiworski, P. Schmidt, S. Schmidt, S. J. Schmitz, R. Schnabel, M. Schneewind, R. M. S. Schofield, A. Schönbeck, K. Schouteden, H. Schuler, B. W. Schulte, B. F. Schutz, E. Schwartz, J. Scott, S. M. Scott, T. C. Seetharamu, M. Seglar-Arroyo, Y. Sekiguchi, D. Sellers, A. S. Sengupta, D. Sentenac, E. G. Seo, J. W. Seo, V. Sequino, G. Servignat, Y. Setyawati, T. Shaffer, M. S. Shahriar, M. A. Shaikh, B. Shams, L. Shao, P. Sharma, S. Sharma-Chaudhary, P. Shawhan, N. S. Shcheblanov, A. Sheela, B. Shen, K. G. Shepard, Y. Shikano, M. Shikauchi, K. Shimode, H. Shinkai, J. Shiota, D. H. Shoemaker, D. M. Shoemaker, R. W. Short, S. ShyamSundar, A. Sider, H. Siegel, M. Sieniawska, D. Sigg, L. Silenzi, M. Simmonds, L. P. Singer, A. Singh, D. Singh, M. K. Singh, A. Singha, A. M. Sintes, V. Sipala, V. Skliris, B. J. J. Slagmolen, T. J. Slaven-Blair, J. Smetana, J. R. Smith, L. Smith, R. J. E. Smith, J. Soldateschi, S. N. Somala, K. Somiya, K. Soni, S. Soni, V. Sordini, F. Sorrentino, N. Sorrentino, R. Soulard, T. Souradeep, E. Sowell, V. Spagnuolo, A. P. Spencer, M. Spera, P. Spinicelli, A. K. Srivastava, V. Srivastava, C. Stachie, F. Stachurski, D. A. Steer, J. Steinlechner, S. Steinlechner, N. Stergioulas, P. Stevens, M. StPierre, L. C. Strang, G. Stratta, M. D. Strong, A. Strunk, R. Sturani, A. L. Stuver, M. Suchenek, S. Sudhagar, N. Sueltmann, H. G. Suh, A. G. Sullivan, T. Z. Summerscales, L. Sun, S. Sunil, A. Sur, J. Suresh, P. J. Sutton, Takamasa Suzuki, Takanori Suzuki, B. L. Swinkels, A. Syx, M. J. Szczepańczyk, P. Szewczyk, M. Tacca, H. Tagoshi, S. C. Tait, H. Takahashi, R. Takahashi, A. Takamori, K. Takatani, H. Takeda, M. Takeda, C. J. Talbot, C. Talbot, M. Tamaki, N. Tamanini, D. Tanabe, K. Tanaka, S. J. Tanaka, T. Tanaka, A. J. Tanasijczuk, S. Tanioka, D. B. Tanner, D. Tao, L. Tao, R. D. Tapia, E. N. Tapia San Martín, R. Tarafder, C. Taranto, A. Taruya, J. D. Tasson, M. Teloi, R. Tenorio, L. Terkowski, H. Themann, M. P. Thirugnanasambandam, L. M. Thomas, M. Thomas, P. Thomas, J. E. Thompson, S. R. Thondapu, K. A. Thorne, E. Thrane, J. Tissino, Shubhanshu Tiwari, Srishti Tiwari, V. Tiwari, A. M. Toivonen, A. E. Tolley, T. Tomaru, K. Tomita, T. Tomura, M. Tonelli, A. Toriyama, A. Torres-Forné, C. I. Torrie, M. Toscani, I. Tosta e Melo, E. Tournefier, A. A. Trani, A. Trapananti, F. Travasso, G. Traylor, J. Trenado, M. Trevor, M. C. Tringali, A. Tripathee, L. Troiano, A. Trovato, L. Trozzo, R. J. Trudeau, M. Tse, R. Tso, S. Tsuchida, L. Tsukada, T. Tsutsui, K. Turbang, M. Turconi, C. Turski, H. Ubach, A. S. Ubhi, N. Uchikata, T. Uchiyama, R. P. Udall, T. Uehara, K. Ueno, C. S. Unnikrishnan, T. Ushiba, A. Utina, H. Vahlbruch, N. Vaidya, G. Vajente, A. Vajpeyi, G. Valdes, M. Valentini, S. A. Vallejo-Peña, S. Vallero, V. Valsan, N. van Bakel, M. van Beuzekom, M. van Dael, J. F. J. van den Brand, C. Van Den Broeck, D. C. Vander-Hyde, M. van der Sluys, A. Van de Walle, J. van Dongen, H. van Haevermaet, J. V. van Heijningen, J. Vanosky, M. H. P. M. van Putten, Z. van Ranst, N. van Remortel, M. Vardaro, A. F. Vargas, V. Varma, M. Vasúth, A. Vecchio, G. Vedovato, J. Veitch, P. J. Veitch, J. Venneberg, P. Verdier, D. Verkindt, P. Verma, Y. Verma, S. M. Vermeulen, D. Veske, F. Vetrano, A. Veutro, A. Viceré, S. Vidyant, A. D. Viets, A. Vijaykumar, V. Villa-Ortega, E. T. Vincent, J. -Y. Vinet, S. Viret, A. Virtuoso, S. Vitale, H. Vocca, D. Voigt, E. R. G. von Reis, J. S. A. von Wrangel, S. P. Vyatchanin, L. E. Wade, M. Wade, K. J. Wagner, R. C. Walet, M. Walker, G. S. Wallace, L. Wallace, H. Wang, J. Z. Wang, W. H. Wang, R. L. Ward, J. Warner, M. Was, T. Washimi, N. Y. Washington, K. Watada, D. Watarai, K. E. Wayt, B. Weaver, C. R. Weaving, S. A. Webster, M. Weinert, A. J. Weinstein, R. Weiss, C. M. Weller, R. A. Weller, F. Wellmann, L. Wen, P. Weßels, K. Wette, J. T. Whelan, D. D. White, B. F. Whiting, C. Whittle, J. B. Wildberger, O. S. Wilk, D. Wilken, K. Willetts, D. Williams, M. J. Williams, A. R. Williamson, J. L. Willis, B. Willke, M. Wils, C. C. Wipf, G. Woan, J. Woehler, J. K. Wofford, D. Wong, H. T. Wong, I. C. F. Wong, M. Wright, C. Wu, D. S. Wu, H. Wu, D. M. Wysocki, L. Xiao, V. A. Xu, N. Yadav, H. Yamamoto, K. Yamamoto, M. Yamamoto, T. S. Yamamoto, T. Yamamoto, S. Yamamura, R. Yamazaki, S. Yan, F. W. Yang, K. Z. Yang, L. -C. Yang, Y. -C. Yang, Yang Yang, Yi Yang, M. J. Yap, Z. Yarbrough, S. -W. Yeh, A. B. Yelikar, S. M. C. Yeung, T. Y. Yeung, J. Yokoyama, T. Yokozawa, J. Yoo, H. Yu, H. Yuzurihara, A. Zadrożny, A. J. Zannelli, M. Zanolin, M. Zeeshan, T. Zelenova, J. -P. Zendri, M. Zevin, J. Zhang, L. Zhang, R. Zhang, T. Zhang, Yanqi Zhang, Ya Zhang, C. Zhao, Yue Zhao, Yuhang Zhao, Y. Zheng, H. Zhong, R. Zhou, Z. -H. Zhu, A. B. Zimmerman, M. E. Zucker, J. Zweizig
Abstract: Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass $M>70$ $M_\odot$) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities $0 < e \leq 0.3$ at $0.33$ Gpc$^{-3}$ yr$^{-1}$ at 90\% confidence level.
6.Systematic Investigation of Very Early-Phase Spectra of Type Ia Supernovae
Authors:Mao Ogawa, Keiichi Maeda, Miho Kawabata
Abstract: It has been widely accepted that Type Ia supernovae (SNe Ia) are thermonuclear explosions of a CO white dwarf. However, the natures of the progenitor system(s) and explosion mechanism(s) are still unclarified. Thanks to the recent development of transient observations, they are now frequently discovered shortly after the explosion, followed by rapid spectroscopic observations. In this study, by modeling very early-phase spectra of SNe Ia, we try to constrain the explosion models of SNe Ia. By using the Monte Carlo radiation transfer code, TARDIS, we estimate the properties of their outermost ejecta. We find that the photospheric velocity of normal-velocity supernovae (NV SNe) in the first week is $\sim$15000 km s$^{-1}$. The outer velocity, to which the carbon burning extends, spans the range between $\sim$20000 and 25000 km s$^{-1}$. The ejecta density of NV SNe also shows a large diversity. For high-velocity supernovae (HV SNe) and 1999aa-like SNe, the photospheric velocity is higher, $\sim$20000 km s$^{-1}$. They are different in the photospheric density, with HV SNe having higher density than 1999aa-like SNe. For all these types, we show that the outermost composition is closely related to the outermost ejecta density; the carbon burning layer and the unburnt carbon layer are found in the higher-density and lower-density objects, respectively. This finding suggests that there might be two sequences, the high-density and carbon-poor group (HV SNe and some NV SNe) and the low-density and carbon-rich group (1999aa-like and other NV SNe), which may be associated with different progenitor channels.
7.Transients stemming from collapsing massive stars: The missing pieces to advance joint observations of photons and high-energy neutrinos
Authors:Ersilia Guarini, Irene Tamborra, Raffaella Margutti, Enrico Ramirez-Ruiz
Abstract: Collapsing massive stars lead to a broad range of astrophysical transients, whose multi-wavelength emission is powered by a variety of processes including radioactive decay, activity of the central engine, and interaction of the outflows with a dense circumstellar medium. These transients are also candidate factories of neutrinos with energy up to hundreds of PeV. We review the energy released by such astrophysical objects across the electromagnetic wavebands as well as neutrinos, in order to outline a strategy to optimize multi-messenger follow-up programs. We find that, while a significant fraction of the explosion energy can be emitted in the infrared-optical-ultraviolet (UVOIR) band, the optical signal alone is not optimal for neutrino searches. Rather, the neutrino emission is strongly correlated with the one in the radio band, if a dense circumstellar medium surrounds the transient, and with X-rays tracking the activity of the central engine. Joint observations of transients in radio, X-rays, and neutrinos will crucially complement those in the UVOIR band, breaking degeneracies in the transient parameter space. Our findings call for heightened surveys in the radio and X-ray bands to warrant multi-messenger detections.
8.X-ray reprocessing: Through the eclipse spectra of low mass X-ray binaries with XMM-Newton
Authors:Nafisa Aftab, Biswajit Paul
Abstract: Eclipsing X-ray binaries make an ideal condition to study reprocessed X-rays, as the X-rays detected during eclipse are purely reprocessed while the much brighter primary X-rays are blocked by the companion star. We carried out a comprehensive study of X-ray reprocessing with four eclipsing Low Mass X-ray Binary (LMXB) systems by comparing X-ray spectra during and outside eclipse with \textit{XMM-Newton} EPIC pn observations. The 17 observations of MXB 1659$-$298, AX J1745.6$-$2901, EXO 0748$-$676 and XTE J1710$-$281 give unique features of the systems. For example, X-ray reprocessing characteristics in AX J1745.6$-$2901 is found to be nearly same irrespective of the intensity state; there is an indication of different types of variable warp structures in the inner accretion disk in EXO 0748$-$676, a high out-of-eclipse to eclipse flux ratio in XTE J1710$-$281 inspite of a large size of the accretion disk perhaps indicates low scale height of the accretion disk. The eclipse spectra for some of the LMXB sources are reported for the first time. We have derived the fractional visible area of the accretion disk during maximum eclipse phase for various obscuration geometries. The out-of-eclipse to eclipse flux ratio in LMXBs observed to be smaller compared to that found in High Mass X-ray Binaries. This indicates greater reprocessing in LMXBs despite having less dense, less extended stellar wind from the companion. The X-ray reprocessing efficiencies observed in LMXBs indicate large dependencies of X-ray reprocessing on the scale height of the accretion disk, relative size of the disk compared to the companion and some other unknown factors.
9.Numerical Relativity Estimates of the Remnant Recoil Velocity in Binary Neutron Star Mergers
Authors:Sumeet Kulkarni, Surendra Padamata, Anuradha Gupta, David Radice, Rahul Kashyap
Abstract: We present, for the first time, recoil velocity estimates for binary neutron star mergers using data from numerical relativity simulations. We find that binary neutron star merger remnants can have recoil velocity of the order of a few tens of km/s and as high as $150$ km/s in our dataset. These recoils are attained due to equivalent contributions from the anisotropic gravitational wave emission as well as the asymmetric ejection of dynamical matter during the merger. We provide fits for net recoil velocity as well as its ejecta component as a function of the amount of ejected matter, which may be useful when constraints on the ejected matter are obtained through electromagnetic observations. We also estimate the mass and spin of the remnants and find them to be in the range $[2.34, 3.38] M_{\odot}$ and $[0.63, 0.82]$ respectively, for our dataset.