An inverse Compton origin for the 55 GeV photon in the late afterglow of GRB 130907A

Journal Article · Fri Jun 20 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/788/2/156· OSTI ID:22356584

Tang, Qing-Wen; Wang, Xiang-Yu ^[1]

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1. School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

The extended high-energy gamma-ray (>100 MeV) emission which occurs well after the prompt gamma-ray bursts (GRBs) is usually explained as the afterglow synchrotron radiation. Here we report the analysis of Fermi Large Area Telescope observations of GRB 130907A. A 55 GeV photon compatible with the position of the burst was found about 5 hr after the prompt phase. The probability that this photon is associated with GRB 130907A is higher than 99.96%. The energy of this photon exceeds the maximum synchrotron photon energy at this time and its occurrence thus challenges the synchrotron mechanism as the origin for the extended high-energy >10 GeV emission. Modeling of the broadband spectral energy distribution suggests that such high energy photons can be produced by the synchrotron self-Compton emission of the afterglow.

• OSTI ID: 22356584
• Journal Information: Astrophysical Journal, Vol. 788, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AFTERGLOW
COSMIC GAMMA BURSTS
EMISSION
ENERGY SPECTRA
GAMMA RADIATION
GEV RANGE
MEV RANGE
PHOTONS
PROBABILITY
SIMULATION
SYNCHROTRON RADIATION