Spectral characteristics of gamma-ray bursts observed by the anticoincidence shield of the SIGMA telescope aboard GRANAT

Abstract

view Abstract Citations (8) References (6) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Spectral Characteristics of Gamma-Ray Bursts Observed by the Anticoincidence Shield of the SIGMA Telescope aboard GRANAT Pelaez, Francois ; Bouchet, Laurent ; Jourdain, Elisabeth ; Niel, Michel ; Claret, Arnaud ; Laurent, Philippe ; Lebrun, Francois ; Paul, Jacques ; Terekhov, O. ; Sunyaev, R. ; Kuznetsov, A. ; Denisenko, D. ; Gilfanov, M. ; Churazov, E. ; Khavenson, N. ; Diachkov, A. Abstract The CsI anticoincidence shield of the SIGMA telescope aboard GRANAT has been operating for 3 years as a gamma-ray burst (GRB) detector in the 0.2-15 MeV range. Owing to a high-energy trigger threshold (250 keV), only 25 events have been detected and confirmed as cosmic GRBs. We present here a review of their spectral characteristics, in particular at high energies. The results of model fitting show that some spectra are more compatible with a broken power law than with a single-component law. Such high-energy breaks could be interpreted as photon absorption phenomena in the presence of a strong magnetic field. Publication: The Astrophysical Journal Supplement Series Pub Date: June 1994 DOI: 10.1086/192034 Bibcode: 1994ApJS...92..651P Keywords: Gamma Ray Astronomy; Gamma Ray Bursts; Gamma Ray Spectra; Bremsstrahlung; Gamma Ray Absorption; Magnetic Fields; Pair Production; Photoproduction; Power Spectra; Astronomy; GAMMA RAYS: BURSTS; GAMMA RAYS: OBSERVATIONS; RADIATION MECHANISMS: NONTHERMAL full text sources ADS | data products SIMBAD (25) NED (15)