INTERPRETATION OF THE UNPRECEDENTEDLY LONG-LIVED HIGH-ENERGY EMISSION OF GRB 130427A

Abstract

High-energy photons (>100 MeV) are detected by theFermi/Large Area Telescope from GRB 130427A up to almost one day after the burst, with an extra hard spectral component discovered in the high-energy afterglow. We show that this hard spectral component arises from afterglow synchrotron self-Compton (SSC) emission. This scenario can explain the origin of >10 GeV photons detected up to ∼30, 000 s after the burst, which would be difficult to explain via synchrotron radiation due to the limited maximum synchrotron photon energy. The lower energy multi-wavelength afterglow data can be fitted simultaneously by the afterglow synchrotron emission. The implication of detecting the SSC emission for the circumburst environment is discussed.

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• The Astrophysical Journal Letters - View - PDF
• arXiv (Cornell University) - View - PDF
• DataCite API - View