BATSE spectroscopy results

Abstract

We present preliminary analyses of gamma-ray burst spectra from the BATSE Spectroscopy Detectors. Our conclusions are: (1) No spectral lines have yet been detected in BATSE data from any cosmic gamma-ray burst. This is not surprising as the data for few bright bursts is available, and previous experiments saw lines in only a small fraction of the bursts. (2) Burst spectra show emission up to 20 MeV, with four of eight examined bursts having significant spectral breaks from 1 to 2 MeV. These breaks are consistent with opacity effects due to the interaction of photons with a high magnetic field. (3) Various distance independent parameters from burst spectra and time histories have no correlation with parameters related to distance. In other words, bright bursts look the same as faint bursts. This places a strong constraint on two population models of bursts. (4) The detection time of individual photons is not correlated from detector to detector, as predicted by Mitrofanov's pulsed emission model.