Study of Very Short Gamma-Ray Bursts: New Results from BATSE and Konus

Our recent studies of very short gamma-ray bursts (GRBs) of T90 <=100 ms duration have indicated a significant angular asymmetry and a uniform V/Vmax distribution from the BATSE (Burst and Transient Source Experiment on the Compton Gamma Ray Observatory [CGRO]) data. Here we update these studies, and we extend our research to events observed with Konus, a GRB experiment from Russia on the International Solar Terrestrial Physics/Wind satellite, that gives us new insight into the spectra that was not possible with the BATSE data. Konus has observed 18 events with T90 <=100 ms duration. These events display a considerable number of photons with energies above 1 MeV and have photons above 5 MeV in all cases. These appear to be some of the most energetic photons observed from any class of GRB to date.