BATSE observations of gamma-ray burst spectral diversity

The spectra of 58 bursts observed by the BATSE Spectroscopy Detectors were fit satisfactorily from less than 30 keV to more than an MeV by a 4 parameter model consisting of two power laws with a smooth transition. We find that a distribution of spectral indices is required instead of the low energy E -1 dependence found in previous work. The break energy ranges from less than 100 keV to more than an MeV, peaking below 200 keV ; this suggests that the break is not Lied directly to pair processes in all bursts. We did not find any conclusive correlations among the spectral parameters; our sample is probably inappropriate for the correlations predicted by the cosmological models