Fermi Large Area Telescope Observations of GRB 110625A
Abstract
Gamma-ray bursts (GRBs) that emit photons at GeV energies form a small but significant population of GRBs. However, the number of GRBs whose GeV-emitting period is simultaneously observed in X-rays remains small. We report γ-ray observations of GRB 110625A using Fermi's Large Area Telescope in the energy range 100 MeV-20 GeV. Gamma-ray emission at these energies was clearly detected using data taken between 180 s and 580 s after the burst, an epoch after the prompt emission phase. The GeV light curve differs from a simple power-law decay, and probably consists of two emission periods. Simultaneous Swift X-Ray Telescope observations did not show flaring behaviors as in the case of GRB 100728A. We discuss the possibility that the GeV emission is the synchrotron self-Compton radiation of underlying ultraviolet flares.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2012
- DOI:
- 10.1088/0004-637X/754/2/117
- arXiv:
- arXiv:1206.3946
- Bibcode:
- 2012ApJ...754..117T
- Keywords:
-
- gamma-ray burst: individual: GRB 110625A;
- gamma rays: stars;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 6 pages, 3 figures, 1 table