The Spectrum of GRB 930131 (“Superbowl Burst”) from 20 keV to 200 MeV

Abstract

We have constructed a broadband spectrum for GRB 930131 (the "Superbowl Burst"), ranging from 20 keV to 200 MeV, by combining spectral information from the Gamma Ray Observatory's BATSE, COMPTEL, and EGRET instruments. We present general methods for combining spectra from different time intervals obtained by the same instrument as well as for combining spectra from the same time interval taken by different instruments. The resulting spectrum is remarkably flat (in νF_ν-space) up to high energies. We find that the spectral shape can be successfully fitted by the shocked synchrotron emission model of Tavani. We present evidence that the flatness of the spectrum at high energies is not due to spectral time variability.