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arXiv 2025年

作者： Abdollahi, S. Ajello, M. Alves Batista, R. Baldini, L. Bartolini, C. Bastieri, D. Becerra Gonzalez, J. Bellazzini, R. Berenji, B. Bissaldi, E. Blandford, R.D. Bonino, R. Bruel, P. Buson, S. Cameron, R.A. Caraveo, P.A. Cavazzuti, E. Chiaro, G. Cibrario, N. Ciprini, S. Cristarella Orestano, P. Cutini, S. D’Ammando, F. Di Lalla, N. Dinesh, A. Di Venere, L. Domínguez, A. Fegan, S.J. Fiori, A. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasbarra, C. Gasparrini, D. Germani, S. Giglietto, N. Giliberti, M. Giordano, F. Giroletti, M. Green, D. Grenier, I.A. Guiriec, S. Hashizume, M. Hays, E. Hewitt, J.W. Horan, D. Hou, Xian Karwin, C. Kayanoki, T. Kuss, M. Laviron, A. Lemoine-Goumard, M. Li, Jian Liodakis, I. Liu, Jun-Rong Longo, F. Loparco, F. Lorusso, L. Lubrano, P. Maldera, S. Marcotulli, L. Martí-Devesa, G. Mazziotta, M.N. Mereu, I. Michelson, P.F. Mirabal, N. Mitthumsiri, W. Mizuno, T. Monzani, M.E. Morishita, T. Morselli, A. Moskalenko, I.V. Negro, M. Niwa, R. Omodei, N. Orienti, M. Orlando, E. Ormes, J.F. Paneque, D. Panzarini, G. Persic, M. Pesce-Rollins, M. Pillera, R. Porter, T.A. Principe, G. Rainò, S. Rando, R. Rani, B. Razzano, M. Reimer, A. Reimer, O. Sánchez-Conde, M. Saz Parkinson, P.M. Serini, D. Sgrò, C. Siskind, E.J. Spandre, G. Spinelli, P. Suson, D.J. Tajima, H. Thayer, J.B. Torres, D.F. Wang, Jian-Min Zhao, Zi-Hao Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Instituto de Física Teórica UAM CSIC Universidad Autónoma de Madrid MadridE-28049 Spain Università di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy Università degli studi di Trento via Calepina 14 Trento38122 Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Università di Padova Via F. Marzolo 8 PadovaI-35131 Italy Center for Space Studies and Activities "G. Colombo" University of Padova Via Venezia 15 PadovaI-35131 Italy Instituto de Astrofísica de Canarias Universidad de La Laguna Dpto. Astrofísica Tenerife La Laguna38200 Spain Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy California State University Los Angeles Department of Physics and Astronomy Los AngelesCA90032 United States Dipartimento di Fisica "M. Merlin" dell’Università e del Politecnico di Bari via Amendola 173 BariI-70126 Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics SLAC National Accelerator Laboratory Stanford University StanfordCA94305 United States Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Università degli Studi di Torino TorinoI-10125 Italy Laboratoire Leprince-Ringuet CNRS IN2P3 École polytechnique Institut Polytechnique de Paris Palaiseau91120 France Institut für Theoretische Physik and Astrophysik Universität Würzburg WürzburgD-97074 Germany INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Milano via E. Bassini 15 MilanoI-20133 Italy Italian Space Agency Via del Politecnico snc Roma00133 Italy Istituto Nazionale di Fisica Nucleare Sezione di Roma "Tor Vergata" RomaI-00133 Italy Space Sci

Relativistic jets around supermassive black holes (SMBHs) are well-known powerful γ-ray emitters. In absence of the jets in radio-quiet active galactic nuclei (AGNs), how the SMBHs work in γ-ray bands is still unknown despite of great observational efforts made in the last 3 decades. Considering the previous efforts, we carefully select an AGN sample composed of 37 nearby Seyfert galaxies with ultra-hard X-rays for the goals of γ-ray detections by excluding all potential contamination in this band. Adopting a stacking technique, here we report the significant γ-ray detection (TS = 30.6, or 5.2 σ) from the sample using 15-year Fermi-Large Area Telescope (LAT) observation. We find an average γ-ray luminosity of the sample as (1.5 ± 1.0) × 1040 erg s−1 at energies from 1-300 GeV. Limited by the well-known pair production from the interaction of γ-rays with low energy photons, several GeV γ-rays are found to originate from an extended corona (∼ 2.7 × 106Rg), whereas the canonical much more compact X-ray corona (∼ 10Rg) is responsible for 1 to several GeV γ-rays. The finding of the compact region lends to strong supports to the long-time theoretical expectations, but the extended corona is beyond all the existing models. One promising scenario is that the electron-positron pairs produced in the compact X-ray corona would expand as fireball, similar to that in γ-ray bursts, forming the structure of extended corona. © 2025, CC BY.

关键词： Active Galactic Nuclei

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Planet Masses, Radii, and Orbits from NASA’s K2 Mission

arXiv

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arXiv 2025年

作者： Howard, Andrew W. Sinukoff, Evan Blunt, Sarah Petigura, Erik A. Crossfield, Ian J.M. Isaacson, Howard Kosiarek, Molly Rubenzahl, Ryan A. Brewer, John M. Fulton, Benjamin J. Dressing, Courtney D. Hirsch, Lea A. Knutson, Heather Livingston, John H. Mills, Sean M. Roy, Arpita Weiss, Lauren M. Benneke, Bjorn Ciardi, David R. Christiansen, Jessie L. Cochran, William D. Crepp, Justin R. Gonzales, Erica Hansen, Brad M.S. Hardegree-Ullman, Kevin Howell, Steve B. Lépine, Sébastien Martinez, Arturo O. Rogers, Leslie A. Schlieder, Joshua E. Werner, Michael Polanski, Alex S. Angelo, Isabel Beard, Corey Behmard, Aida Bouma, Luke G. Brinkman, Casey L. Chontos, Ashley Dai, Fei Dalba, Paul A. Giacalone, Steven Grunblatt, Samuel K. Hill, Michelle L. Kane, Stephen R. Lubin, Jack Mayo, Andrew W. Mocnik, Teo Akana Murphy, Joseph M. Rice, Malena Rosenthal, Lee J. Tyler, Dakotah Van Zandt, Judah Yee, Samuel W. Department of Astronomy California Institute of Technology PasadenaCA United States Institute for Astronomy University of Hawaii 2680 Woodlawn Drive HonoluluHI United States Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States Department of Astronomy & Astrophysics University of California Santa CruzCA United States Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Department of Physics & Astronomy University of California Los Angeles Los AngelesCA United States Department of Physics and Astronomy University of Kansas LawrenceKS United States Astronomy Department University of California BerkeleyCA United States Department of Physics and Astronomy San Francisco State University 1600 Holloway Ave. San FranciscoCA94132 United States IPAC - NASA Exoplanet Science Institute California Institute of Technology 770 S. Wilson Ave PasadenaCA United States Department of Chemical & Physical Sciences University of Toronto Mississauga 3359 Mississauga Road MississaugaONL5L 1C6 Canada Geological and Planetary Sciences California Institute of Technology PasadenaCA United States Astrobiology Center 2-21-1 Osawa Mitaka Tokyo181-8588 Japan National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Astronomical Science Program The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States Astrophysics & Space Institute Schmidt Sciences New YorkNY10011 United States Department of Physics and Astronomy University of Notre Dame Notre DameIN46556 United States Institut de Recherche sur les Exoplanètes Université de Montréal MontréalQC Canada McDonald Observatory Center for Planetary Systems Habitability The University of Texas AustinTX United States Department of Physics and Astronomy University of Toledo ToledoOH4

We report the masses, sizes, and orbital properties of 86 planets orbiting 55 stars observed by NASA’s K2 Mission with follow-up Doppler measurements by the HIRES spectrometer at the W. M. Keck Observatory and the Automated Planet Finder at Lick Observatory. Eighty-one of the planets were discovered from their transits in the K2 photometry, while five were found based on subsequent Doppler measurements of transiting planet host stars. The sizes of the transiting planets range from Earth-size to larger than Jupiter (1–3 R is typical), while the orbital periods range from less than a day to a few months. For 32 of the planets, the Doppler signal was detected with significance greater than 5-σ (51 were detected with >3-σ significance). An important characteristic of this catalog is the use of uniform analysis procedures to determine stellar and planetary properties. This includes the transit search and fitting procedures applied to the K2 photometry, the Doppler fitting techniques applied to the radial velocities, and the spectral modeling to determine bulk stellar parameters. Such a uniform treatment will make the catalog useful for statistical studies of the masses, densities, and system architectures of exoplanetary systems. This work also serves as a data release for all previously unpublished RVs and associated stellar activity indicators obtained by our team for these systems, along with derived stellar and planet parameters. © 2025, CC BY.

关键词： NASA

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Limits on the Ejecta Mass During the Search for Kilonovae Associated with Neutron Star-Black Hole Mergers: A case study of S230518h, GW230529, S230627c and the Low-Significance Candidate S240422ed

arXiv

引用

arXiv 2025年

作者： Pillas, M. Antier, S. Ackley, K. Ahumada, T. Akl, D. de Almeida, L. Anand, S. Andrade, C. Andreoni, I. Bostroem, K.A. Bulla, M. Burns, E. Cabrera, T. Chang, S. Choi, H. O’Connor, B. Coughlin, M.W. Corradi, W. Gibbs, A.R. Dietrich, T. Dornic, D. Ducoin, J.-G. Duverne, P.-A. Dyer, M. Eggenstein, H.-B. Freeberg, M. Fausnaugh, M. Fong, W. Foucart, F. Frostig, D. Guessoum, N. Gupta, V. Hello, P. Hosseinzadeh, G. Hu, L. Hussenot-Desenonges, T. Im, M. Jayaraman, R. Jeong, M. Karambelkar, V. Karpov, S. Kasliwal, M. Kilpatrick, C.D. Kim, S. Kochiashvili, N. Kunnumkai, K. Lamoureux, M. Lee, C.U. Lourie, N. Lyman, J. Magnani, F. Mašek, M. Mo, G. Molham, M. Navarete, F. O’Neill, D. Nicholl, M. Nitz, A.H. Noysena, K. Paek, G.S.H. Palmese, A. Poggiani, R. Pradier, T. Pyshna, O. Rajabov, Y. Rastinejad, J.C. Sand, D.J. Shawhan, P. Shrestha, M. Simcoe, R. Smartt, S.J. Steeghs, D. Stein, R. Stevance, H.F. Sun, M. Takey, A. Toivonen, A. Turpin, D. Ulaczyk, K. Wold, A. Wouters, T. STAR Institute Liege University Allée du Six Août Liege19C B-4000 Belgium Université de la Côte d’Azur ARTEMIS Nice France IJCLab Univ Paris-Saclay CNRS IN2P3 Orsay France Department of Physics University of Warwick Gibbet Hill Road CoventryCV4 7AL United Kingdom Division of Physics Mathematics and Astronomy California Institute of Technology PasadenaCA91125 United States American University of Sharjah Physics Department PO Box 26666 Sharjah United Arab Emirates Laboratório Nacional de Astrofísica Rua Estado Unidos 154 - MG Itajubá37504-364 Brazil School of Physics and Astronomy University of Minnesota MinneapolisMN55455 United States Department of Physics and Astronomy University of North Carolina at Chapel Hill Chapel HillNC27599-3255 United States Steward Observatory University of Arizona 933 North Cherry Avenue TucsonAZ85721-0065 United States Department of Physics and Earth Science University of Ferrara via Saragat 1 FerraraI-44122 Italy INFN Sezione di Ferrara via Saragat 1 FerraraI-44122 Italy INAF Osservatorio Astronomico d’Abruzzo via Mentore Maggini snc Teramo64100 Italy Department of Physics & Astronomy Louisiana State University Baton RougeLA70803 United States McWilliams Center for Cosmology and Astrophysics Department of Physics Carnegie Mellon University PittsburghPA15213 United States SNU Astronomy Research Center Astronomy Program Department of Physics & Astronomy Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of Lunar and Planetary Laboratory University of Arizona 1629 East University Boulevard TucsonAZ85721-0092 United States Institut für Physik und Astronomie Universität Potsdam Haus 28 Karl-Liebknecht-Str. 24/25 Potsdam14476 Germany Am Mühlenberg 1 Potsdam14476 Germany CPPM Aix Marseille Univ CNRS IN2P3 CPPM Marseille France Université Paris Cité CNRS Astroparticule et Cosmologie ParisF-75013 France Astrophysics Research Cluster School of Mathematical and

Neutron star–black hole (NSBH) mergers, detectable via their gravitational-wave (GW) emission, are expected to produce kilonovae (KNe). Four NSBH candidates have been identified and followed-up by more than fifty instruments since the start of the fourth GW Observing Run (O4), in May 2023, up to July 2024;however, no confirmed associated KN has been detected. This study evaluates ejecta properties from multi-messenger observations to understand the absence of detectable KN: we use GW public information and joint observations taken from 05.2023 to 07.2024 (LVK, ATLAS, DECam, GECKO, GOTO, GRANDMA, SAGUARO, TESS, WINTER, ZTF). First, our analysis on followup observation strategies shows that, on average, more than 50% of the simulated KNe associated with NSBH mergers reach their peak luminosity around one day after merger in the g, r, i- bands, which is not necessarily covered for each NSBH GW candidate. We also analyze the trade-off between observation efficiency and the intrinsic properties of the KN emission, to understand the impact on how these constraints affect our ability to detect the KN, and underlying ejecta properties for each GW candidate. In particular, we can only confirm the kilonova was not missed for 1% of the GW230529 and S230627c sky localization region, given the large sky localization error of GW230529 and the large distance for S230627c and, their respective KN faint luminosities. More constraining, for S230518h, we infer the dynamical ejecta and post-merger disk wind ejecta mdyn, mwind ☉ and the viewing angle θ > 25◦. Similarly, the non-astrophysical origin of S240422ed is likely further confirmed by the fact that we would have detected even a faint KN at the time and presumed distance of the S240422ed event candidate, within a minimum 45% credible region of the sky area, that can be larger depending on the KN scenario. Copyright © 2025, The Authors. All rights reserved.

关键词： Black holes

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First Constraints on the Epoch of Reionization Using the non-Gaussianity of the Kinematic Sunyaev-Zel’dovich Effect from the South Pole Telescope and Herschel-SPIRE Observations

arXiv

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arXiv 2024年

作者： Raghunathan, S. Ade, P.A.R. Anderson, A.J. Ansarinejad, B. Archipley, M. Austermann, J.E. Balkenhol, L. Beall, J.A. Benabed, K. Bender, A.N. Benson, B.A. Bianchini, F. Bleem, L.E. Bock, J. Bouchet, F.R. Bryant, L. Camphuis, E. Carlstrom, J.E. Cecil, T.W. Chang, C.L. Chaubal, P. Chiang, H.C. Chichura, P.M. Chou, T.-L. Citron, R. Coerver, A. Crawford, T.M. Crites, A.T. Cukierman, A. Daley, C. Dibert, K.R. Dobbs, M.A. Doussot, A. Dutcher, D. Everett, W. Feng, C. Ferguson, K.R. Fichman, K. Foster, A. Galli, S. Gallicchio, J. Gambrel, A.E. Gardner, R.W. Ge, F. George, E.M. Goeckner-Wald, N. Gualtieri, R. Guidi, F. Guns, S. Gupta, N. de Haan, T. Halverson, N.W. Hivon, E. Holder, G.P. Holzapfel, W.L. Hood, J.C. Hrubes, J.D. Hryciuk, A. Huang, N. Hubmayr, J. Irwin, K.D. Kéruzoré, F. Khalife, A.R. Knox, L. Korman, M. Kornoelje, K. Kuo, C.-L. Lee, A.T. Levy, K. Li, D. Lowitz, A.E. Lu, C. Maniyar, A. Martsen, E.S. McMahon, J.J. Menanteau, F. Millea, M. Montgomery, J. Moran, C. Corbett Nakato, Y. Natoli, T. Nibarger, J.P. Noble, G.I. Novosad, V. Omori, Y. Padin, S. Pan, Z. Paschos, P. Patil, S. Phadke, K.A. Prabhu, K. Pryke, C. Quan, W. Rahimi, M. Rahlin, A. Reichardt, C.L. Rouble, M. Ruhl, J.E. Saliwanchik, B.R. Schaffer, K.K. Schiappucci, E. Sievers, C. Smecher, G. Sobrin, J.A. Stark, A.A. Stephen, J. Suzuki, A. Tandoi, C. Thompson, K.L. Thorne, B. Trendafilova, C. Tucker, C. Umilta, C. Veach, T. Vieira, J.D. Viero, M.P. Wan, Y. Wang, G. Whitehorn, N. Wu, W.L.K. Yefremenko, V. Young, M.R. Zebrowski, J.A. Zemcov, M. Center for AstroPhysical Surveys National Center for Supercomputing Applications UrbanaIL61801 United States School of Physics and Astronomy Cardiff University CardiffCF24 3YB United Kingdom Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States School of Physics University of Melbourne ParkvilleVIC3010 Australia Department of Astronomy University of Illinois Urbana-Champaign 1002 West Green Street UrbanaIL61801 United States NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States Department of Physics University of Colorado BoulderCO80309 United States Institut d’Astrophysique de Paris UMR 7095 CNRS & Sorbonne Université 98 bis boulevard Arago Paris75014 France High-Energy Physics Division Argonne National Laboratory 9700 South Cass Avenue. LemontIL60439 United States Kavli Institute for Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Department of Physics Stanford University 382 Via Pueblo Mall StanfordCA94305 United States SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States California Institute of Technology PasadenaCA91125 United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA91109 United States Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics McGill Space Institute McGill University 3600 Rue University MontrealQCH3A 2T8 Canada School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Durban South Africa Unive

We report results from an analysis aimed at detecting the trispectrum of the kinematic Sunyaev-Zel’dovich (kSZ) effect by combining data from the South Pole Telescope (SPT) and Herschel-SPIRE experiments over a 100 deg2 field. The SPT observations combine data from the previous and current surveys, namely SPTpol and SPT-3G, to achieve depths of 4.5, 3, and 16 µK-arcmin in bands centered at 95, 150, and 220 GHz. For SPIRE, we include data from the 600 and 857 GHz bands. We reconstruct the velocity-induced large-scale correlation of the small-scale kSZ signal with a quadratic estimator that uses two cosmic microwave background (CMB) temperature maps, constructed by optimally combining data from all the frequency bands. We reject the null hypothesis of a zero trispectrum at 10.3σ level. However, the measured trispectrum contains contributions from both the kSZ and other undesired components, such as CMB lensing and astrophysical foregrounds, with kSZ being sub-dominant. We use the Agora simulations to estimate the expected signal from CMB lensing and astrophysical foregrounds. After accounting for the contributions from CMB lensing and foreground signals, we do not detect an excess kSZ-only trispectrum and use this non-detection to set constraints on reionization. By applying a prior based on observations of the Gunn-Peterson trough, we obtain an upper limit on the duration of reionization of (formula presented). We find these constraints are fairly robust to foregrounds assumptions. This trispectrum measurement is independent of, but consistent with, Planck’s optical depth measurement. This result is the first constraint on the epoch of reionization using the non-Gaussian nature of the kSZ signal. © 2024, CC BY.

关键词： Kinematics

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UV/Optical disk reverberation lags despite a faint X-ray corona in the AGN Mrk 335

arXiv

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arXiv 2023年

作者： Kara, Erin Barth, Aaron J. Cackett, Edward M. Gelbord, Jonathan Montano, John Li, Yan-Rong Santana, Lisabeth Horne, Keith Alston, William N. Buisson, Douglas Chelouche, Doron Du, Pu Fabian, Andrew C. Fian, Carina Gallo, Luigi Goad, Michael R. Grupe, Dirk González Buitrago, Diego H. Hernández Santisteban, Juan V. Kaspi, Shai Hu, Chen Komossa, S. Kriss, Gerard A. Lewin, Collin Lewis, Tiffany Loewenstein, Michael Lohfink, Anne Masterson, Megan McHardy, Ian M. Mehdipour, Missagh Miller, Jake Panagiotou, Christos Parker, Michael L. Pinto, Ciro Remillard, Ron Reynolds, Christopher Rogantini, Daniele Wang, Jian-Min Wang, Jingyi Wilkins, Dan MIT Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics and Astronomy 4129 Frederick Reines Hall University of California IrvineCA92697-4575 United States Department of Physics and Astronomy Wayne State University 666 W. Hancock St DetroitMI48201 United States Spectral Sciences Inc. 4 Fourth Ave. BurlingtonMA01803 United States Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences 19B Yuquan Road Beijing100049 China Department of Physics and Astronomy University of Pittsburgh 3941 O’Hara St PittsburghPA15260 United States SUPA School of Physics and Astronomy North Haugh St. AndrewsKY16 9SS United Kingdom Villanueva de la Canada MadridE-28691 Spain Department of Physics Faculty of Natural Sciences University of Haifa Haifa3498838 Israel Haifa Research Center for Theoretical Physics and Astrophysics University of Haifa Haifa3498838 Israel Institute of Astronomy University of Cambridge Madingley Road CambridgeCB3 0HA United Kingdom School of Physics and Astronomy and Wise observatory Tel Aviv University Tel Aviv6997801 Israel Department of Astronomy and Physics Saint Mary’s University 923 Robie Street HalifaxNSB3H 3C3 Canada School of Physics and Astronomy University of Leicester University Road LeicesterLE1 7RH United Kingdom Department of Physics Geology and Engineering Technology Northern Kentucky University 1 Nunn Dr. Highland HeightsKY41099 United States Instituto de Astronomía Universidad Nacional Autónoma de México Km 103 Carretera Tijuana-Ensenada B.C. Ensenada22860 Mexico Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 Bonn53121 Germany Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States NASA Postdoctoral Program Fellow Astroparticle Physics Lab Goddard Space Flight Center United States Astrophysics Science Division NASA Goddard S

We present the first results from a 100-day Swift, NICER and ground-based X-ray/UV/optical reverberation mapping campaign of the Narrow-Line Seyfert 1 Mrk 335, when it was in an unprecedented low X-ray flux state. Despite dramatic suppression of the X-ray variability, we still observe UV/optical lags as expected from disk reverberation. Moreover, the UV/optical lags are consistent with archival observations when the X-ray luminosity was > 10 times higher. Interestingly, both low- and high-flux states reveal UV/optical lags that are 6 − 11 times longer than expected from a thin disk. These long lags are often interpreted as due to contamination from the broad line region, however the u band excess lag (containing the Balmer jump from the diffuse continuum) is less prevalent than in other AGN. The Swift campaign showed a low X-ray-to-optical correlation (similar to previous campaigns), but NICER and ground-based monitoring continued for another two weeks, during which the optical rose to the highest level of the campaign, followed ∼ 10 days later by a sharp rise in X-rays. While the low X-ray countrate and relatively large systematic uncertainties in the NICER background make this measurement challenging, if the optical does lead X-rays in this flare, this indicates a departure from the zeroth-order reprocessing picture. If the optical flare is due to an increase in mass accretion rate, this occurs on much shorter than the viscous timescale. Alternatively, the optical could be responding to an intrinsic rise in X-rays that is initially hidden from our line-of-sight. © 2023, CC BY.

关键词： Reverberation

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Construction status and prospects of the Hyper-Kamiokande project

Construction status and prospects of the Hyper-Kamiokande pr...

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37th International Cosmic Ray Conference, ICRC 2021

作者： Itow, Yoshitaka Abe, K. Adrich, P. Aihara, H. Akutsu, R. Alekseev, I. Ali, A. Alj Hakim, Y.I. Ameli, F. Anthony, L.H.V. Araya, A. Asaoka, Y. Aushev, V. Ballester, F. Bandac, I. Barbi, M. Barr, G. Batkiewicz-Kwasniak, M. Bellato, M. Berardi, V. Bernard, L. Bernardini, E. Berns, L. Bhadra, S. Bian, J. Blanchet, A. Blondel, A. Boiano, A. Bolognesi, S. Bonavera, L. Booth, N. Bordoni, S. Borjabad, S. Boschi, T. Bose, D. Boyd, S.B. Bozza, C. Bravar, A. Bronner, C. Brown, L. Bubak, A. Buchowicz, A. Buizza Avanzini, M. Cafagna, F.S. Calabria, N.F. Calvo-Mozota, J.M. Cao, S. Carroll, A. Catanesi, M.G. Cebriàn, S. Chakraborty, S. Choi, J.H. Choubey, S. Cicerchia, M. Coleman, J. Collazuol, G. Cuen-Rochin, S. Danilov, M. Díaz López, G. De la Fuente, E. de Perio, P. De Rosa, G. Dealtry, T. Densham, C.J. Dergacheva, A. Deshmukh, N. Devi, M.M. Di Lodovico, F. Di Meo, P. Di Palma, I. Doyle, T.A. Drakopoulou, E. Drapier, O. Dumarchez, J. Eklund, L. El Hedri, S. Ellis, J. Emery, S. Esmaili, A. Esteve, R. Fedotov, S. Feng, J. Fernandez, P. Fernández-Martinez, E. Ferrario, P. Ferrazzi, B. Finch, A. Finley, C. Fiorillo, G. Fitton, M. Friend, M. Fujii, Y. Fujisawa, C. Fukuda, Y. Galinski, G. Gao, J. Garde, C. Garfagnini, A. Garode, S. Gialanella, L. Giganti, C. Gomez-Cadenas, J.J. Gonin, M. González-Nuevo, J. Gorin, A. Gornea, R. Gousy-Leblanc, V. Gramegna, F. Grassi, M. Grella, G. Guigue, M. Hadley, D.R. Harada, M. Hartz, M. Hassani, S. Hastings, N.C. Hayato, Y. Hernando-Morata, J.A. Herrero, V. Hiraide, K. Holin, A. Hoshina, K. Hultqvist, K. Iacob, F. Ichikawa, A.K. Idrissi Ibnsalih, W. Ieki, K. Ikeda, M. Ioannisian, A. Ishida, T. Ishidoshiro, K. Ishino, H. Ishitsuka, M. Israel, H.T. Ito, H. Itow, Y. Izumi, N. Izumiyama, S. Jakkapu, M. Jamieson, B. Jang, J.S. Jo, H.S. Jonsson, P. Joo, K.K. Kajita, T. Kakuno, H. Kameda, J. Kaneshima, R. Kano, Y. Karlen, D. Kataoka, Y. Kato, A. Katori, T. Kazarian, N. Khabibullin, M. Institute for Space-Earth Environmental Research Kobayashi-Maskawa Institute for the Origin of Particles and the Universe Nagoya University Aichi Nagoya Japan University of Tokyo Institute for Cosmic Ray Research Kamioka Observatory Kamioka Japan University of Tokyo Institutes for Advanced Study Kashiwa Japan University of Tokyo Next-generation Neutrino Science Organization Kamioka Japan National Centre for Nuclear Research Warsaw Poland University of Tokyo Department of Physics Tokyo Japan TRIUMF VancouverBC Canada P.N.Lebedev Physical Institute of the Russian Academy of Sciences Moscow Russia Kyoto University Department of Physics Kyoto Japan Imperial College London Department of Physics London United Kingdom INFN Sezione di Roma Università Sapienza Dipartimento di Fisica Roma Italy University of Tokyo Earthquake Research Institute Tokyo Japan Kyiv National University Department of Nuclear Physics Kyiv Ukraine Valencia Spain Laboratorio Subterráneo de Canfranc Estación Canfranc Spain University of Regina Department of Physics ReginaSK Canada Oxford University Department of Physics Oxford United Kingdom H. Niewodniczański Institute of Nuclear Physics PAN Cracow Poland INFN Sezione di Padova Università di Padova Dipartimento di Fisica Padova Italy INFN Sezione di Bari Università e Politecnico di Bari Bari Italy Ecole Polytechnique IN2P3-CNRS Laboratoire Leprince-Ringuet Palaiseau France Tokyo Institute of Technology Department of Physics Tokyo Japan York University Department of Physics and Astronomy TorontoON Canada University of California Irvine Department of Physics and Astronomy IrvineCA United States Laboratoire de Physique Nucleaire et de Hautes Energie IN2P3 CNRS Sorbonne Universitè Paris France INFN Sezione di Napoli Napoli Italy IRFU CEA Universitè Paris-Saclay Gif-sur-Yvette France University of Oviedo Applied Mathematical Modeling Group Department of Physics Oviedo Spain University of Victoria Department of

The Hyper-Kamiokande project is a 258-kton Water Cherenkov together with a 1.3-MW high-intensity neutrino beam from the Japan Proton Accelerator Research Complex (J-PARC). The inner detector with 186-kton fiducial volume is viewed by 20-inch photomultiplier tubes (PMTs) and multi-PMT modules, and thereby provides state-of-the-art of Cherenkov ring reconstruction with thresholds in the range of few MeVs. The project is expected to lead to precision neutrino oscillation studies, especially neutrino CP violation, nucleon decay searches, and low energy neutrino astronomy. In 2020, the project was officially approved and construction of the far detector was started at Kamioka. In 2021, the excavation of the access tunnel and initial mass production of the newly developed 20-inch PMTs was also started. In this paper, we present a basic overview of the project and the latest updates on the construction status of the project, which is expected to commence operation in 2027. © Copyright owned by the author(s).

关键词： Photomultipliers

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Candidate Electromagnetic Counterpart to the Binary Black Hole Merger Gravitational-Wave Event S190521g*

引用

Physical Review Letters 2020年第25期124卷 251102-251102页

作者： M. J. Graham K. E. S. Ford B. McKernan N. P. Ross D. Stern K. Burdge M. Coughlin S. G. Djorgovski A. J. Drake D. Duev M. Kasliwal A. A. Mahabal S. van Velzen J. Belecki E. C. Bellm R. Burruss S. B. Cenko V. Cunningham G. Helou S. R. Kulkarni F. J. Masci T. Prince D. Reiley H. Rodriguez B. Rusholme R. M. Smith M. T. Soumagnac Cahill Center for Astronomy and Astrophysics California Institute of Technology 1200 E. California Boulevard Pasadena California 91125 USA Department of Science CUNY-BMCC 199 Chambers Street New York New York 10007 USA Department of Astrophysics American Museum of Natural History Central Park West New York New York 10028 USA Physics Program The Graduate Center CUNY New York New York 10016 USA Institute for Astronomy University of Edinburgh Royal Observatory Blackford Hill Edinburgh EH9 3 HJ United Kingdom Jet Propulsion Laboratory California Institute of Technology Pasadena California 91109 USA Division of Physics Mathematics and Astronomy California Institute of Technology Pasadena California 91125 USA School of Physics and Astronomy University of Minnesota Minneapolis Minnesota 55455 USA Department of Astronomy University of Maryland College Park Maryland 20742 USA Center for Cosmology and Particle Physics New York University New York New York 10003 USA Caltech Optical Observatories California Institute of Technology Pasadena California 91125 USA DIRAC Institute Department of Astronomy University of Washington 3910 15th Avenue NE Seattle Washington 98195 USA Astrophysics Science Division NASA Goddard Space Flight Center MC 661 Greenbelt Maryland 20771 USA Joint Space-Science Institute University of Maryland College Park Maryland 20742 USA IPAC California Institute of Technology 1200 E. California Boulevard Pasadena California 91125 USA Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley California 94720 USA Department of Particle Physics and Astrophysics Weizmann Institute of Science Rehovot 76100 Israel

We report the first plausible optical electromagnetic counterpart to a (candidate) binary black hole merger. Detected by the Zwicky Transient Facility, the electromagnetic flare is consistent with expectations for a kicked binary black hole merger in the accretion disk of an active galactic nucleus [B. McKernan, K. E. S. Ford, I. Bartos et al., Astrophys. J. Lett. 884, L50 (2019)] and is unlikely [

关键词： Sky surveys Transient & explosive astronomical phenomena

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The radius of PSR J0740+6620 from nicer and XMM-Newton data

arXiv

引用

arXiv 2021年

作者： Miller, M.C. Lamb, F.K. Dittmann, A.J. Bogdanov, S. Arzoumanian, Z. Gendreau, K.C. Guillot, S. Ho, W.C.G. Lattimer, J.M. Loewenstein, M. Morsink, S.M. Ray, P.S. Wolff, M.T. Baker, C.L. Cazeau, T. Manthripragada, S. Markwardt, C.B. Okajima, T. Pollard, S. Cognard, I. Cromartie, H.T. Fonseca, E. Guillemot, L. Kerr, M. Parthasarathy, A. Pennucci, T.T. Ransom, S. Stairs, I. Department of Astronomy and Joint Space-Science Institute University of Maryland College ParkMD20742-2421 United States Illinois Center for Advanced Studies of the Universe and Department of Physics University of Illinois at Urbana-Champaign 1110 West Green Street UrbanaIL61801-3080 United States Department of Astronomy University of Illinois at Urbana-Champaign 1002 West Green Street UrbanaIL61801-3074 United States Columbia Astrophysics Laboratory Columbia University 550 West 120th Street New YorkNY10027 United States X-Ray Astrophysics Laboratory NASA Goddard Space Flight Center Code 662 GreenbeltMD20771 United States IRAP CNRS 9 avenue du Colonel Roche Toulouse Cedex 4F-31028 France Université de Toulouse CNES UPS-OMP ToulouseF-31028 France Department of Physics and Astronomy Haverford College 370 Lancaster Avenue HaverfordPA19041 United States Department of Physics and Astronomy Stony Brook University Stony BrookNY11794-3800 United States Department of Astronomy University of Maryland College ParkMD20742-2421 United States Center for Research and Exploration in Space Science and Technology NASA/GSFC GreenbeltMD20771 United States Department of Physics University of Alberta 4-183 CCIS EdmontonABT6G 2E1 Canada Space Science Division U.S. Naval Research Laboratory WashingtonDC20375 United States Applied Engineering and Technology NASA Goddard Space Flight Center GreenbeltMD20771 United States Instrument Systems and Technology Division NASA Goddard Space Flight Center GreenbeltMD20771 United States Astrophysics Science Division NASA Goddard Space Flight Center GreenbeltMD20771 United States Station de Radioastronomie de Nançay Observatoire de Paris CNRS/INSU Université d'Orléans Nançay18330 France 9 Laboratoire de Physique et Chimie de l'Environnement CNRS 3A Avenue de la Recherche Scientifique Orléans Cedex 245071 France Cornell Center for Astrophysics and Planetary Science and Department of Astronomy Cornell Unive

PSR J0740+6620 has a gravitational mass of 2:08 ± 0:07 Mo, which is the highest reliably determined mass of any neutron star. As a result, a measurement of its radius will provide unique insight into the properties of neutron star core matter at high densities. Here we report a radius measurement based on fits of rotating hot spot patterns to Neutron Star Interior Composition Explorer (NICER) and X-ray Multi-Mirror (XMM-Newton) X-ray observations. We find that the equatorial circumferential radius of PSR J0740+6620 is 13:7+2:6-1:5 km (68%). We apply our measurement, combined with the previous NICER mass and radius measurement of PSR J0030+0451, the masses of two other ∼ 2 Mo pulsars, and the tidal deformability constraints from two gravitational wave events, to three different frameworks for equation of state modeling, and find consistent results at ∼ 1:5-3 times nuclear saturation density. For a given framework, when all measurements are included the radius of a 1:4 Mo neutron star is known to ±4% (68% credibility) and the radius of a 2:08 Mo neutron star is known to ±5%. The full radius range that spans the ±1σ credible intervals of all the radius estimates in the three frameworks is 12:45±0:65 km for a 1:4 Mo neutron star and 12:35±0:75 km for a 2:08 Mo neutron star. Copyright © 2021, The Authors. All rights reserved.

关键词： Equations of state

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Selective dynamical imaging of interferometric data

arXiv

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arXiv 2024年

作者： Farah, Joseph Galison, Peter Akiyama, Kazunori Bouman, Katherine L. Bower, Geoffrey C. Chael, Andrew Fuentes, Antonio Gómez, José L. Honma, Mareki Johnson, Michael D. Kofuji, Yutaro Marrone, Daniel P. Moriyama, Kotaro Narayan, Ramesh Pesce, Dominic W. Tiede, Paul Wielgus, Maciek Zhao, Guang-Yao Alberdi, Antxon Alef, Walter Algaba, Juan Carlos Anantua, Richard Asada, Keiichi Azulay, Rebecca Bach, Uwe Baczko, Anne-Kathrin Ball, David Baloković, Mislav Barrett, John Bauböck, Michi Benson, Bradford A. Bintley, Dan Blackburn, Lindy Blundell, Raymond Boland, Wilfred Boyce, Hope Bremer, Michael Brinkerink, Christiaan D. Brissenden, Roger Britzen, Silke Broderick, Avery E. Broguiere, Dominique Bronzwaer, Thomas Bustamante, Sandra Byun, Do-Young Carlstrom, John E. Ceccobello, Chiara Chan, Chi-Kwan Chatterjee, Koushik Chatterjee, Shami Chen, Ming-Tang Chen, Yongjun Cho, Ilje Christian, Pierre Conroy, Nicholas S. Conway, John E. Cordes, James M. Crawford, Thomas M. Crew, Geoffrey B. Cruz-Osorio, Alejandro Cui, Yuzhu Davelaar, Jordy De Laurentis, Mariafelicia Deane, Roger Dempsey, Jessica Desvignes, Gregory Doeleman, Sheperd S. Dhruv, Vedant Dzib Quijano, Sergio Abraham Eatough, Ralph P. Emami, Razieh Falcke, Heino Fish, Vincent L. Fomalont, Ed Ford, H. Alyson Fraga-Encinas, Raquel Freeman, William T. Friberg, Per Fromm, Christian M. Gammie, Charles F. García, Roberto Gentaz, Olivier Georgiev, Boris Goddi, Ciriaco Gold, Roman Gómez-Ruiz, Arturo I. Gu, Minfeng Gurwell, Mark Hada, Kazuhiro Haggard, Daryl Hecht, Michael H. Hesper, Ronald Ho, Luis C. Ho, Paul Huang, Chih-Wei L. Huang, Lei Hughes, David H. Ikeda, Shiro Impellizzeri, C.M. Violette Inoue, Makoto Issaoun, Sara James, David J. Jannuzi, Buell T. Janssen, Michael Jeter, Britton Jiang, Wu Jimenez-Rosales, Alejandra Jorstad, Svetlana Joshi, Abhishek V. Jung, Taehyun Karami, Mansour Karuppusamy, Ramesh Kawashima, Tomohisa Keating, Garrett K. Kettenis, Mark Kim, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kino, Motoki Koay, Jun Yi Kocherlakota, Prashant Koch, Patrick Las Cumbres Observatory 6740 Cortona Drive Suite 102 GoletaCA93117-5575 United States Department of Physics University of California Santa BarbaraCA93106-9530 United States Black Hole Initiative Harvard University 20 Garden Street CambridgeMA02138 United States Department of History of Science Harvard University CambridgeMA02138 United States Department of Physics Harvard University CambridgeMA02138 United States Massachusetts Institute of Technology Haystack Observatory 99 Millstone Road WestfordMA01886 United States National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Center for Astrophysics — Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States California Institute of Technology 1200 East California Boulevard PasadenaCA91125 United States Institute of Astronomy and Astrophysics Academia Sinica 645 N. A’ohoku Place HiloHI96720 United States Princeton Center for Theoretical Science Princeton University Jadwin Hall PrincetonNJ08544 United States NASA Hubble Fellowship Program Einstein Fellow United States Instituto de Astrofísica de Andalucía CSIC Glorieta de la Astronomía s/n GranadaE-18008 Spain Mizusawa VLBI Observatory National Astronomical Observatory of Japan 2-12 Hoshigaoka Mizusawa Iwate Oshu023-0861 Japan 2-21-1 Osawa Tokyo Mitaka181-8588 Japan Department of Astronomy Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Steward Observatory Department of Astronomy University of Arizona 933 N. Cherry Ave. TucsonAZ85721 United States Department of Physics and Astronomy University of Waterloo 200 University Avenue West WaterlooONN2L 3G1 Canada Waterloo Centre for Astrophysics University of Waterloo WaterlooONN2L 3G1 Canada Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany Department of Physics Faculty of Science Universiti Malaya Kuala Lumpur50603 Malaysia Department of Physics & Ast

Recent developments in very-long-baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of the EHT’s (u, v) coverage presents a challenge when attempting to resolve highly time-variable sources. We demonstrate that the changing (u, v) coverage of the EHT can contain regions of time over the course of a single observation that facilitate dynamical imaging. These optimal time regions typically have projected baseline distributions that are approximately angularly isotropic and radially homogeneous. We derive a metric of coverage quality based on baseline isotropy and density that is capable of ranking array configurations by their ability to produce accurate dynamical reconstructions. We compare this metric to existing metrics in the literature, and investigate their utility by performing dynamical reconstructions on synthetic data from simulated EHT observations of sources with simple orbital variability. We then use these results to make recommendations for imaging the 2017 EHT Sgr A∗ dataset. © 2024, CC BY.

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The blue compact dwarf galaxy VCC848 formed by dwarf-dwarf merging

arXiv

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arXiv 2020年

作者： Zhang, Hong-Xin Paudel, Sanjaya Smith, Rory Duc, Pierre-Alain Puzia, Thomas H. Peng, Eric W. Côte, Patrick Ferrarese, Laura Boselli, Alessandro Wang, Kaixiang Oh, Se-Heon CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Hefei Anhui230026 China School of Astronomy and Space Science University of Science and Technology of China Hefei230026 China Department of Astronomy Center for Galaxy Evolution Research Yonsei University Seoul03722 Korea Republic of Korea Astronomy and Space Science Institute Daejeon305-348 Korea Republic of Universit de Strasbourg CNRS Observatoire astronomique de Strasbourg UMR 7550 StrasbourgF-67000 France Instituto de Astrofsica Pontificia Universidad Catlica de Chile Macul Santiago7820436 Chile Department of Astronomy Peking University Beijing100871 China Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China National Research Council of Canada Herzberg Astronomy and Astrophysics Program 5071 West Saanich Road VictoriaBCV9E 2E7 Canada UMR 7326 MarseilleF-13388 France Department of Physics and Astronomy Sejong University 209 Neungdong-ro Gwangjin-gu Seoul Korea Republic of

It has long been speculated that many starburst or compact dwarf galaxies are resulted from dwarfdwarf galaxy merging, but unequivocal evidence for this possibility has rarely been reported in the literature. We present the first study of deep optical broadband images of a gas-dominated blue compact dwarf galaxy (BCD) VCC848 (M∗2×108Mo) which hosts extended stellar shells and thus is confirmed to be a dwarf-dwarf merger. VCC848 is located in the outskirts of the Virgo Cluster. By analyzing the stellar light distribution, we found that VCC848 is the result of a merging between two dwarf galaxies with a primary-to-secondary mass ratio 5 for the stellar components and 2 for the presumed dark matter halos. The secondary progenitor galaxy has been almost entirely disrupted. The age-mass distribution of photometrically selected star cluster candidates in VCC848 implies that the cluster formation rate (CFR, ∝ star formation rate) was enhanced by a factor of ∼ 7 - 10 during the past ∼ 1 Gyr. The merging-induced enhancement of CFR peaked near the galactic center a few hundred Myr ago and has started declining in the last few tens of Myr. The current star formation activities, as traced by the youngest clusters, mainly occur at large galactocentric distances ( 1 kpc). The fact that VCC848 is still (atomic) gas-dominated after the period of most violent collision suggests that gas-rich dwarf galaxy merging can result in BCD-like remnants with extended atomic gas distribution surrounding a blue compact center, in general agreement with previous numerical simulations. Copyright © 2020, The Authors. All rights reserved.

关键词： Merging

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