EGRET detection of high energy gamma rays from the gamma-ray burst of 3 May 1991.
Abstract
On May 3, 1991, the Energetic Gamma Ray Experiment Telescope on the Compton Gamma Ray Observatory detected a gamma-ray burst both in the energy measurement subsystem and independently in the spark chamber assembly. Six individual photons were detected in the spark chamber, allowing a determination of the burst arrival direction which was l(II) = 171.9 deg +/- 1.3 deg, b(II) = 5.3 deg +/- 1.1 deg. Three energy spectra were measured from 1 to 200 MeV; they were measured during the first second after the Burst and Transient Sources Experiment trigger, the next two seconds, and the subsequent four seconds. The first two spectra exhibit a similar differential spectra index of about -2.2 with no apparent high-energy cut-off. By the time of the third spectrum, an additional soft component is evident.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- February 1992
- Bibcode:
- 1992A&A...255L..13S
- Keywords:
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- Gamma Ray Astronomy;
- Gamma Ray Bursts;
- Gamma Ray Spectra;
- Gamma Ray Telescopes;
- Energy Spectra;
- Gamma Ray Observatory;
- Photons;
- Spectrum Analysis;
- Astrophysics