A. U. Abeysekara, A. Archer, Wystan Benbow, Ralph Bird, Robert Brose, M. Buchovecky, V. Bugaev, M. P. Connolly, Wei Cui, Manel Errando, A. Falcone, Qi Feng, John P. Finley, A. Flinders, L. Fortson, Amy Furniss, Gerard H. Gillanders, M. Huetten, David Hanna, O. Hervet, J. Holder, G. Hughes, T. B. Humensky, Caitlin A. Johnson, Philip Kaaret, P. Kar, N. Kelley-Hoskins, M. Kertzman, David Kieda, Maria Krause, F. Krennrich, M. J. Lang, T. T. Y. Lin, Gernot Maier, S. McArthur, P. Moriarty, Reshmi Mukherjee, R. A. Ong, N. Park, Jeremy S. Perkins, A. Petrashyk, Martin Pohl, Alexis Popkow, Elisa Pueschel, J. Quinn, K. Ragan, P. T. Reynolds, Gregory T. Richards, E. Roache, C. Rulten, I. Sadeh, M. Santander, G. H. Sembroski, Karlen Shahinyan, J. Tyler, S. P. Wakely, O. M. Weiner, A. Weinstein, R. M. Wells, P. Wilcox, Alina Wilhelm, David A. Williams, B. Zitzer, Indrek Vurm, Andrei Beloborodov
- On 2015 March 23, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) responded to a Swift-Burst Alert Telescope (BAT) detection of a gamma-ray burst, with observations beginning 270 s after the onset of BAT emission, and only 135 s after the main BAT emission peak. No statistically significant signal is detected above 140 GeV. The VERITAS upper limit on the fluence in a 40-minute integration corresponds to about 1% of the prompt fluence. Our limit is particularly significant because the very-high-energy (VHE) observation started only similar to 2 minutes after the prompt emission peaked, and Fermi-Large Area Telescope observations of numerous other bursts have revealed that the high-energy emission is typically delayed relative to the prompt radiation and lasts significantly longer. Also, the proximity of GRB 150323A (z = 0.593) limits the attenuation by the extragalactic background light to similar to 50% at 100-200 GeV. We conclude that GRB 150323A had an intrinsically very weak high-energy afterglow, or that theOn 2015 March 23, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) responded to a Swift-Burst Alert Telescope (BAT) detection of a gamma-ray burst, with observations beginning 270 s after the onset of BAT emission, and only 135 s after the main BAT emission peak. No statistically significant signal is detected above 140 GeV. The VERITAS upper limit on the fluence in a 40-minute integration corresponds to about 1% of the prompt fluence. Our limit is particularly significant because the very-high-energy (VHE) observation started only similar to 2 minutes after the prompt emission peaked, and Fermi-Large Area Telescope observations of numerous other bursts have revealed that the high-energy emission is typically delayed relative to the prompt radiation and lasts significantly longer. Also, the proximity of GRB 150323A (z = 0.593) limits the attenuation by the extragalactic background light to similar to 50% at 100-200 GeV. We conclude that GRB 150323A had an intrinsically very weak high-energy afterglow, or that the GeV spectrum had a turnover below similar to 100 GeV. If the GRB exploded into the stellar wind of a massive progenitor, the VHE non-detection constrains the wind density parameter to be A greater than or similar to 3 x 10(11) g . cm(-1), consistent with a standard Wolf-Rayet progenitor. Alternatively, the VHE emission from the blast wave would be weak in a very tenuous medium such as the interstellar medium, which therefore cannot be ruled out as the environment of GRB 150323A.…
MetadatenAuthor details: | A. U. Abeysekara, A. Archer, Wystan BenbowORCiD, Ralph BirdORCiD, Robert BroseORCiDGND, M. Buchovecky, V. Bugaev, M. P. Connolly, Wei CuiORCiD, Manel ErrandoORCiD, A. Falcone, Qi FengORCiD, John P. FinleyORCiD, A. Flinders, L. Fortson, Amy FurnissORCiD, Gerard H. GillandersORCiD, M. Huetten, David HannaORCiD, O. Hervet, J. Holder, G. Hughes, T. B. Humensky, Caitlin A. JohnsonORCiD, Philip KaaretORCiD, P. Kar, N. Kelley-Hoskins, M. Kertzman, David KiedaORCiD, Maria KrauseORCiD, F. Krennrich, M. J. LangORCiD, T. T. Y. Lin, Gernot MaierORCiD, S. McArthur, P. Moriarty, Reshmi MukherjeeORCiD, R. A. Ong, N. Park, Jeremy S. PerkinsORCiD, A. Petrashyk, Martin PohlORCiDGND, Alexis PopkowORCiD, Elisa PueschelORCiD, J. Quinn, K. Ragan, P. T. Reynolds, Gregory T. RichardsORCiD, E. Roache, C. Rulten, I. Sadeh, M. Santander, G. H. Sembroski, Karlen ShahinyanORCiD, J. Tyler, S. P. Wakely, O. M. Weiner, A. Weinstein, R. M. Wells, P. Wilcox, Alina WilhelmORCiDGND, David A. WilliamsORCiD, B. Zitzer, Indrek VurmORCiD, Andrei Beloborodov |
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DOI: | https://doi.org/10.3847/1538-4357/aab371 |
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ISSN: | 0004-637X |
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ISSN: | 1538-4357 |
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Title of parent work (English): | The astrophysical journal : an international review of spectroscopy and astronomical physics |
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Publisher: | IOP Publ. Ltd. |
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Place of publishing: | Bristol |
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Publication type: | Article |
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Language: | English |
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Date of first publication: | 2018/04/10 |
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Publication year: | 2018 |
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Creating corporation: | VERITAS Collaboration |
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Release date: | 2021/12/10 |
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Tag: | gamma rays: general; gamma-ray burst: general; gamma-ray burst: individual (GRB 150323A) |
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Volume: | 857 |
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Issue: | 1 |
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Number of pages: | 6 |
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Funding institution: | U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada; Estonian Research Council [PUT1112] |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
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DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie |
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| 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
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Peer review: | Referiert |
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Publishing method: | Open Access / Green Open-Access |
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