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Erratum: 'Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies. II. Spatially Resolved Mass Outflow Rates for the QSO2 Markarian 34' (2018, ApJ, 867, 88)* †

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The Astrophysical Journal 2019年第2期881卷

作者： M. Revalski D. Dashtamirova D. M. Crenshaw S. B. Kraemer T. C. Fischer H. R. Schmitt C. L. Gnilka J. Schmidt M. Elvis G. Fabbiano T. Storchi-Bergmann W. P. Maksym P. Gandhi Department of Physics and Astronomy Georgia State University 25 Park Place Suite 605 Atlanta GA 30303 USA National Science Foundation Graduate Research Fellow (DGE-1550139). Institute for Astrophysics and Computational Sciences Department of Physics The Catholic University of America Washington DC 20064 USA Astrophysics Science Division Goddard Space Flight Center Code 665 Greenbelt MD 20771 USA James Webb Space Telescope NASA Postdoctoral Program Fellow. Naval Research Laboratory Washington DC 20375 USA Designer/Developer for the Astrophysics Source Code Library. Harvard-Smithsonian Center for Astrophysics 60 Garden St. Cambridge MA 02138 USA Departamento de Astronomia Universidade Federal do Rio Grande do Sul IF CP 15051 91501-970 Porto Alegre RS Brazil Department of Physics and Astronomy University of Southampton Southampton SO17 3RT UK

KMT-2016-BLG-0212: First KMTNET-only discovery of a substellar companion

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arXiv 2018年

作者： Hwang, K.-H. Kim, H.-W. Kim, D.-J. Gould, A. Albrow, M.D. Chung, S.-J. Han, C. Jung, Y.K. Ryu, Y.-H. Shin, I.-G. Shvartzvald, Y. Yee, J.C. Zang, W. Zhu, W. Cha, S.-M. Kim, S.-L. Lee, C.-U. Lee, D.-J. Lee, Y. Park, B.-G. Pogge, R.W. Korea Astronomy and Space Science Institute Daejon34055 Korea Republic of Max-Planck-Institute for Astronomy Königstuhl 17 Heidelberg69117 Germany Department of Astronomy Ohio State University 140 W. 18th Ave. ColumbusOH43210 United States University of Canterbury Department of Physics and Astronomy Private Bag 4800 Christchurch8020 New Zealand Korea University of Science and Technology 217 Gajeong-ro Yuseong-gu Daejeon34113 Korea Republic of Department of Physics Chungbuk National University Cheongju28644 Korea Republic of Harvard-Smithsonian CfA 60 Garden St. CambridgeMA02138 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States NASA Postdoctoral Program Fellow Physics Department and Tsinghua Centre for Astrophysics Tsinghua University Beijing100084 China Department of Physics Zhejiang University Hangzhou310058 China Canadian Institute for Theoretical Astrophysics University of Toronto 60 St George Street TorontoONM5S 3H8 Canada School of Space Research Kyung Hee University Yongin Kyeonggi17104 Korea Republic of

We present the analysis of KMT-2016-BLG-0212, a low flux-variation (Iflux−var ∼ 20) microlensing event, which is well-covered by high-cadence data from the three Korea Microlensing Telescope Network (KMTNet) telescopes. The event shows a short anomaly that is incompletely covered due to the brief visibility intervals that characterize the early microlensing season when the anomaly occurred. We show that the data are consistent with two classes of solutions, characterized respectively by low-mass brown-dwarf (q = 0.037) and sub-Neptune (q −4) companions, respectively. Future high-resolution imaging should easily distinguish between these solutions. Copyright © 2018, The Authors. All rights reserved.

关键词： Telescopes

The KMTNet/K2-C9 (Kepler) data release

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arXiv 2018年

作者： Kim, H.-W. Hwang, K.-H. Kim, D.-J. Albrow, M.D. Cha, S.-M. Chung, S.-J. Gould, A. Han, C. Jung, Y.K. Kim, S.-L. Lee, C.-U. Lee, D.-J. Lee, Y. Park, B.-G. Pogge, R.W. Ryu, Y.-H. Shin, I.-G. Shvartzvald, Y. Yee, J.C. Zang, W. Zhu, W. Korea Astronomy and Space Science Institute Daejon34055 Korea Republic of University of Canterbury Department of Physics and Astronomy Private Bag 4800 Christchurch8020 New Zealand School of Space Research Kyung Hee University Yongin Kyeonggi17104 Korea Republic of Astronomy and Space Science Major Korea University of Science and Technology Daejeon34113 Korea Republic of Department of Astronomy Ohio State University 140 W. 18th Ave. ColumbusOH43210 United States Max-Planck-Institute for Astronomy Königstuhl 17 Heidelberg69117 Germany Department of Physics Chungbuk National University Cheongju28644 Korea Republic of Harvard-Smithsonian CfA 60 Garden St. CambridgeMA02138 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Physics Department and Tsinghua Centre for Astrophysics Tsinghua University Beijing100084 China Department of Physics Zhejiang University Hangzhou310058 China Canadian Institute for Theoretical Astrophysics University of Toronto 60 St George Street TorontoONM5S 3H8 Canada NASA Postdoctoral Program Fellow

We present Korea Microlensing Telescope Network (KMTNet) light curves for microlensing-event candidates in the Kepler K2 C9 field having peaks within 3 effective timescales of the Kepler observations. These include 181 "clear microlensing" and 84 "possible microlensing" events found by the KMTNet event finder, plus 56 other events found by OGLE and/or MOA that were not found by KMTNet. All data for the first two classes are immediately available for public use without restriction. Copyright © 2018, The Authors. All rights reserved.

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QUASI-PERIODIC BEHAVIOR OF MINI-DISKS IN BINARY BLACK HOLES APPROACHING MERGER

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arXiv 2017年

作者： Bowen, Dennis B. Mewes, Vassilios Campanelli, Manuela Noble, Scott C. Krolik, Julian H. Zilhão, Miguel Center for Computational Relativity and Gravitation Rochester Institute of Technology RochesterNY14623 United States Department of Physics and Engineering Physics University of Tulsa TulsaOK74104 United States NASA Postdoctoral Program Senior Fellow Goddard Space Flight Center GreenbeltMD20771 United States Department of Physics and Astronomy Johns Hopkins University BaltimoreMD21218 United States CENTRA Departamento de Física Instituto Superior Técnico Universidade de Lisboa Lisboa1049 Portugal

We present the first magnetohydrodynamic simulation in which a circumbinary disk around a relativistic binary black hole feeds mass to individual accretion disks ("mini-disks") around each black hole. Mass flow through the accretion streams linking the circumbinary disk to the mini-disks is modulated quasi-periodically by the streams’ interaction with a nonlinear m = 1 density feature, or "lump", at the inner edge of the circumbinary disk: the stream supplying each mini-disk comes into phase with the lump at a frequency 0.74 times the binary orbital frequency. Because the binary is relativistic, the tidal truncation radii of the mini-disks are not much larger than their innermost stable circular orbits;consequently, the mini-disks’ inflow times are shorter than the conventional estimate and are comparable to the stream modulation period. As a result, the mini-disks are always in inflow disequilibrium, with their masses and spiral density wave structures responding to the stream’s quasi-periodic modulation. The fluctuations in each mini-disk’s mass are so large that as much as 75% of the total mini-disk mass can be contained within a single mini-disk. Such quasi-periodic modulation of the mini-disk structure may introduce distinctive time-dependent features in the binary’s electromagnetic emission. Copyright © 2017, The Authors. All rights reserved.

关键词： Magnetohydrodynamics

OGLE-2017-BLG-0537: Microlensing event with a resolvable lens in 5 years from high-resolution follow-up observations

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arXiv 2018年

作者： Jung, Y.K. Han, C. Udalski, A. Gould, A. Albrow, M.D. Chung, S.-J. Hwang, K.-H. Lee, C.-U. Ryu, Y.-H. Shin, I.-G. Shvartzvald, Y. Yee, J.C. Zang, W. Zhu, W. Cha, S.-M. Kim, D.-J. Kim, H.-W. Kim, S.-L. Lee, D.-J. Lee, Y. Park, B.-G. Pogge, R.W. Kim, W.-T. Mroz, P. Poleski, R. Skowron, J. Szymanski, M.K. Soszynski, I. Kozlowski, S. Pietrukowicz, P. Ulaczyk, K. Pawlak, M. Korea Astronomy and Space Science Institute Daejon34055 Korea Republic of Department of Physics Chungbuk National University Cheongju28644 Korea Republic of Warsaw University Observatory Al. Ujazdowskie 4 Warszawa00-478 Poland Department of Astronomy Ohio State University 140 W. 18th Ave. ColumbusOH43210 United States Max Planck Institute for Astronomy Königstuhl 17 HeidelbergD-69117 Germany University of Canterbury Department of Physics and Astronomy Private Bag 4800 Christchurch8020 Korea University of Science and Technology 217 Gajeong-ro Yuseong-gu Daejeon34113 Harvard-Smithsonian Center for Astrophysics 60 Garden St. CambridgeMA02138 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Physics Department Tsinghua Centre for Astrophysics Tsinghua University Beijing100084 China Department of Physics Zhejiang University Hangzhou310058 China Canadian Institute for Theoretical Astrophysics University of Toronto 60 St George Street TorontoONM5S3H8 Canada School of Space Research Kyung Hee University Yongin Kyeonggi17104 Korea Republic of Department of Physics & Astronomy Seoul National University Seoul08826 Korea Republic of KMTNet Collaboration OGLE Collaboration NASA Postdoctoral Program Fellow

We present the analysis of the binary-lens microlensing event OGLE-2017-BLG-0537. The light curve of the event exhibits two strong caustic-crossing spikes among which the second caustic crossing was resolved by high-cadence surveys. It is found that the lens components with a mass ratio ∼ 0.5 are separated in projection by ∼ 1.3θE, where θE is the angular Einstein radius. Analysis of the caustic-crossing part yields θE = 1.77 ± 0.16 mas and a lens-source relative proper motion of μ = 12.4±1.1 mas yr-1. The measured μ is the third highest value among the events with measured proper motions and ∼ 3 times higher than the value of typical Galactic bulge events, making the event a strong candidate for follow-up observations to directly image the lens by separating it from the source. From the angular Einstein radius combined with the microlens parallax, t is estimated that the lens is composed of two main-sequence stars with masses M1 ∼ 0.4 Mo and M2 ∼ 0.2 Mo located at a distance of DL ∼ 1.2 kpc. However, the physical lens parameters are not very secure due to the weak microlens-parallax signal, and thus we cross check the parameters by conducting a Bayesian analysis based on the measured Einstein radius and event timescale combined with the blending constraint. From this, we find that the physical parameters estimated from the Bayesian analysis are consistent with those based on the measured microlens parallax. Resolving the lens from the source can be done in about 5 years from highresolution follow-up observations and this will provide a rare opportunity to test and refine the microlensing model. Copyright © 2018, The Authors. All rights reserved.

关键词： Geometrical optics

OGLE-2017-BLG-0373Lb: A Jovian mass-ratio planet exposes a new accidental microlensing degeneracy

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arXiv 2018年

作者： Skowron, J. Ryu, Y.-H. Hwang, K.-H. Udalski, A. Mroz, P. Kozlowski, S. Soszinski, I. Pietrukowicz, P. Szymánski, M.K. Poleski, R. Ulaczyk, K. Pawlak, M. Rybicki, K. Iwanek, P. Albrow, M.D. Chung, S.-J. Gould, A. Han, C. Jung, Y.K. Shin, I.-G. Shvartzvald, Y. Yee, J.C. Zang, W. Zhu, W. Cha, S.-M. Kim, D.-J. Kim, H.-W. Kim, S.-L. Lee, C.-U. Lee, D.-J. Lee, Y. Park, B.-G. Pogge, R.W. Warsaw University Observatory Al. Ujazdowskie 4 Warszawa00-478 Poland Korea Astronomy and Space Science Institute Daejon34055 Korea Republic of Department of Astronomy Ohio State University 140 W. 18th Ave. ColumbusOH43210 United States University of Canterbury Department of Physics and Astronomy Private Bag 4800 Christchurch8020 New Zealand Korea University of Science and Technology Daejeon34113 Korea Republic of Max-Planck-Institute for Astronomy Konigstuhl 17 Heidelberg69117 Germany Department of Physics Chungbuk National University Cheongju28644 Korea Republic of Harvard-Smithsonian CfA 60 Garden St. CambridgeMA02138 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Physics Department Tsinghua Centre for Astrophysics Tsinghua University Beijing100084 China Department of Physics Zhejiang University Hangzhou310058 China Canadian Institute for Theoretical Astrophysics University of Toronto 60 St George Street TorontoONM5S3H8 Canada School of Space Research Kyung Hee University Yongin Kyeonggi17104 Korea Republic of NASA Postdoctoral Program Fellow

We report the discovery of microlensing planet OGLE-2017-BLG-0373Lb. We show that while the planet-host system has an unambiguous microlens topology, there are two geometries within this topology that fit the data equally well, which leads to a factor 2.5 difference in planet-host mass ratio, i.e., q = 1.5 × 10-3vs. q = 0.6iÁ10.3. We show that this is an "accidental degeneracy" in the sense that it is due to a gap in the data. We dub it "the caustic-chirality degeneracy". We trace the mathematical origins of this degeneracy, which should enable similar degenerate solutions to be easily located in the future. A Bayesian estimate, based on a Galactic model, yields a host mass M = 0.25+0.30-0.15Mo at a distance DL = 5.9+1.3-1.95kpc. The lens-source relative proper motion is relatively fast, μ = 9 mas/yr, which implies that the host mass and distance can be determined by high-resolution imaging after about 10 years. The same observations could in principle resolve the discrete degeneracy in q, but this will be more challenging. Copyright © 2018, The Authors. All rights reserved.

关键词： Bayesian networks

Classifier for gravitational-wave inspiral signals in nonideal single-detector data

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Physical Review D 2017年第10期96卷 104015-104015页

作者： S. J. Kapadia T. Dent T. Dal Canton Department of Physics University of Arkansas Fayetteville Arkansas 72701 USA Albert-Einstein-Institut (Max-Planck-Institut für Gravitationsphysik) Callinstr. 38 Hannover Germany Center for Gravitation Cosmology and Astrophysics University of Wisconsin-Milwaukee Milwaukee Wisconsin 53201 USA Leibniz-Universität Hannover D-30167 Hannover Germany NASA Postdoctoral Program Fellow Goddard Space Flight Center Greenbelt Maryland 20771 USA

We describe a multivariate classifier for candidate events in a templated search for gravitational-wave (GW) inspiral signals from neutron-star–black-hole (NS-BH) binaries, in data from ground-based detectors where sensitivity is limited by non-Gaussian noise transients. The standard signal-to-noise ratio (SNR) and chi-squared test for inspiral searches use only properties of a single matched filter at the time of an event; instead, we propose a classifier using features derived from a bank of inspiral templates around the time of each event, and also from a search using approximate sine-Gaussian templates. The classifier thus extracts additional information from strain data to discriminate inspiral signals from noise transients. We evaluate a random forest classifier on a set of single-detector events obtained from realistic simulated advanced LIGO data, using simulated NS-BH signals added to the data. The new classifier detects a factor of 1.5–2 more signals at low false positive rates as compared to the standard “reweighted SNR” statistic, and does not require the chi-squared test to be computed. Conversely, if only the SNR and chi-squared values of single-detector events are available, random forest classification performs nearly identically to the reweighted SNR.

关键词： Experimental studies of gravity General relativity Gravitational waves

Packed ultra-wideband mapping array (PUMA∗): A radio telescope for cosmology and transients

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arXiv 2019年

作者： Slosar, Anže Ahmed, Zeeshan Alonso, David Amin, Mustafa A. Ansari, Réza Arena, Evan J. Bandura, Kevin Battaglia, Nicholas Blazek, Jonathan Bull, Philip Castorina, Emanuele Chang, Tzu-Ching Connor, Liam Davé, Romeel Dvorkin, Cora van Engelen, Alexander Ferraro, Simone Flauger, Raphael Foreman, Simon Frisch, Josef Green, Daniel Holder, Gilbert Jacobs, Daniel Johnson, Matthew C. Dillon, Joshua S. Karagiannis, Dionysios Kaurov, Alexander A. Knox, Lloyd Liu, Adrian Loverde, Marilena Ma, Yin-Zhe Masui, Kiyoshi W. McClintock, Thomas Meerburg, Pieter D. Moodley, Kavilan Münchmeyer, Moritz Newburgh, Laura B. Ng, Cherry Nomerotski, Andrei O'Connor, Paul Obuljen, Andrej Padmanabhan, Hamsa Parkinson, David Xavier Prochaska, J. Rajendran, Surjeet Rapetti, David Saliwanchik, Benjamin Schaan, Emmanuel Sehgal, Neelima Richard Shaw, J. Sheehy, Chris Sheldon, Erin Shirley, Raphael Silverstein, Eva Slatyer, Tracy Slosar, Anže Stankus, Paul Stebbins, Albert Timbie, Peter T. Tucker, Gregory S. Tyndall, William Villaescusa-Navarro, Francisco Wallisch, Benjamin White, Martin Brookhaven National Laboratory SLAC National Accelerator Laboratory Menlo ParkCA94025 United States University of Oxford OxfordOX1 3RH United Kingdom Department of Physics & Astronomy Rice University HoustonTX77005 United States Université Paris-Sud LAL UMR 8607 Orsay CedexF-91898 France CNRS/IN2P3 OrsayF-91405 France Brookhaven National Laboratory UptonNY11973 United States Drexel University PhiladelphiaPA19104 United States CSEE West Virginia University MorgantownWV26505 United States Center for Gravitational Waves and Cosmology West Virginia University MorgantownWV26505 United States Cornell University IthacaNY14853 United States Observatoire de Sauverny Versoix1290 Switzerland Queen Mary University of London LondonE1 4NS United Kingdom Department of Physics & Astronomy University of the Western Cape Cape Town7535 South Africa Department of Physics University of California Berkeley BerkeleyCA94720 United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Anton Pannekoek Institute for Astronomy University of Amsterdam Amsterdam1098 XH Netherlands University of Edinburgh EdinburghEH8 9YL United Kingdom Department of Physics Harvard University CambridgeMA02138 United States Canadian Institute for Theoretical Astrophysics University of Toronto TorontoONM5S 3H8 Canada Arizona State University TempeAZ85287 United States Lawrence Berkeley National Laboratory BerkeleyCA94720 United States University of California San Diego San DiegoCA92093 United States Department of Physics University of Illinois at Urbana-Champaign UrbanaIL61801 United States Department of Physics and Astronomy York University TorontoONM3J 1P3 Canada Perimeter Institute WaterlooONN2L 2Y5 Canada Department of Astronomy University of California Berkeley BerkeleyCA94720 United States Dipartimento di Fisica e Astronomia "G. Galilei" Università degli Studi di Padova Padova35131 Italy Istituto Naziona

We present a concept for an ultra-wide band, high-sensitivity and low-resolution radio telescope array operating at 200 MHz-1100 MHz, which is optimized for cosmology with 21 cm intensity mapping in the post-reionization era, but also addresses other science goals amenable to such observations, including Fast Radio Bursts (FRBs), pulsar monitoring and transients as a part of multi-messenger observations. Our project is named PUMA (Packed Ultra-wideband Mapping Array) and is an evolution of the Stage II 21 cm experiment concept. This idea grew out of deliberations of the Cosmic Visions Dark Energy Committee, a Department of Energy panel tasked with investigating possible future directions for the DOE HEP program in the field of dark energy science, and more generally low-redshift survey science. In two reports [1, 2], the idea of a DOE-led 21 cm experiment was advocated, followed by the development of a concept within the 21 cm working group. This has culminated in the 21cm Roadmap document [3], which was published on the arXiv in October 2018 and submitted to the DOE. For the decadal survey, the concept has been significantly updated following new insights, mostly regarding the feasibility of the ultra-wide bandwidth feed antennas and the theoretical modelling of the expected signal. Copyright © 2019, The Authors. All rights reserved.

关键词： Ultra-wideband (UWB)

Fermi and Swift Observations of Grb 190114C: Tracing The Evolution of High-Energy Emission From Prompt to Afterglow

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arXiv 2019年

作者： Ajello, M. Arimoto, M. Axelsson, M. Baldini, L. Barbiellini, G. Bastieri, D. Bellazzini, R. Berretta, A. Bissaldi, E. Blandford, R.D. Bonino, R. Bottacini, E. Bregeon, J. Bruel, P. Buehler, R. Burns, E. Buson, S. Cameron, R.A. Caputo, R. Caraveo, P.A. Cavazzuti, E. Chen, S. Chiaro, G. Ciprini, S. Cohen-Tanugi, J. Costantin, D. Cutini, S. D’Ammando, F. DeKlotz, M. de la Torre Luque, P. de Palma, F. Desai, A. Lalla, N. Di Venere, L. Di Dirirsa, F. Fana Fegan, S.J. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Gill, R. Giordano, F. Giroletti, M. Granot, J. Green, D. Grenier, I.A. Grondin, M.-H. Guiriec, S. Hays, E. Horan, D. Jóhannesson, G. Kocevski, D. Kovacevic, M. Kuss, M. Larsson, S. Latronico, L. Lemoine-Goumard, M. Li, J. Liodakis, I. Longo, F. Loparco, F. Lovellette, M.N. Lubrano, P. Maldera, S. Malyshev, D. Manfreda, A. Martí-Devesa, G. Mazziotta, M.N. McEnery, J.E. Mereu, I. Meyer, M. Michelson, P.F. Mitthumsiri, W. Mizuno, T. Monzani, M.E. Moretti, E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Omodei, N. Orienti, M. Orlando, E. Palatiello, M. Paliya, V.S. Paneque, D. Pei, Z. Persic, M. Pesce-Rollins, M. Petrosian, V. Piron, F. Poon, H. Porter, T.A. Principe, G. Racusin, J.L. Rainò, S. Rando, R. Rani, B. Razzano, M. Razzaque, S. Reimer, A. Reimer, O. Ryde, F. Parkinson, P.M. Saz Serini, D. Sgrò, C. Siskind, E.J. Spandre, G. Spinelli, P. Tajima, H. Takagi, K. Takahashi, M.N. Tak, D. Thayer, J.B. Thompson, D.J. Torres, D.F. Troja, E. Valverde, J. van Klaveren, B. Wood, K. Yassine, M. Zaharijas, G. Bhat, P.N. Briggs, M.S. Cleveland, W. Giles, M. Goldstein, A. Hui, M. Malacaria, C. Preece, R. Roberts, O. Veres, P. von Kienlin, A. Cenko, S.B. O’Brien, P. Beardmore, A.P. Lien, A. Osborne, J.P. Tohuvavohu, A. D’Elia, V. Da, A. Perri, M. Gropp, J. Klingler, N. Capalbi, M. Tagliaferri, G. Stamatikos, M. Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Faculty of Mathematics and Physics Institute of Science and Engineering Kanazawa University Kakuma Kanazawa Ishikawa920-1192 Department of Physics Stockholm University AlbaNova StockholmSE-106 91 Sweden Department of Physics KTH Royal Institute of Technology AlbaNova StockholmSE-106 91 Sweden Università di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy Dipartimento di Fisica Università di Trieste TriesteI-34127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Università di Padova PadovaI-35131 Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Dipartimento di Fisica Università degli Studi di Perugia PerugiaI-06123 Italy Dipartimento di Fisica "M. Merlin" dell’Università e del Politecnico di Bari BariI-70126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari 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 Department of Physics and Astronomy University of Padova Vicolo Osservatorio 3 PadovaI-35122 Italy Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany NASA Goddard Space Flight Center GreenbeltMD20771 United States NASA Postdoctoral Program Fellow United States In

We report on the observations of gamma-ray burst (GRB) 190114C by the Fermi Gamma-ray Space Telescope and the Neil Gehrels Swift Observatory. The prompt gamma-ray emission was detected by the Fermi Gamma-ray Burst Monitor (GBM), the Fermi Large Area Telescope (LAT), and the Swift Burst Alert Telescope (BAT) and the long-lived afterglow emission was subsequently observed by the GBM, LAT, Swift X-ray Telescope (XRT), and Swift UV Optical Telescope (UVOT). The early-time observations reveal multiple emission components that evolve independently, with a delayed power-law component that exhibits significant spectral attenuation above 40 MeV in the first few seconds of the burst. This power-law component transitions to a harder spectrum that is consistent with the afterglow emission observed by the XRT at later times. This afterglow component is clearly identifiable in the GBM and BAT light curves as a slowly fading emission component on which the rest of the prompt emission is superimposed. As a result, we are able to observe the transition from internal shock to external shock dominated emission. We find that the temporal and spectral evolution of the broadband afterglow emission can be well modeled as synchrotron emission from a forward shock propagating into a wind-like circumstellar environment. We estimate the initial bulk Lorentz factor using the observed high-energy spectral cutoff. Considering the onset of the afterglow component, we constrain the deceleration radius at which this forward shock begins to radiate in order to estimate the maximum synchrotron energy as a function of time. We find that even in the LAT energy range, there exist high-energy photons that are in tension with the theoretical maximum energy that can be achieved through synchrotron emission from a shock. These violations of the maximum synchrotron energy are further compounded by the detection of very high energy (VHE) emission above 300 GeV by MAGIC concurrent with our observations. We con

关键词： Stars