Early Gamma Rays from Supernovae

Abstract

The recent y-ray pulses observed from the Vela satellites are interpreted as y-ray pulses from Type II hydrogen-spectrum supernovae in distant galaxies. The origin of the y-rays is presumed to be the bremsstrahlung and inverse-Compton-heated photons originating from the high-iontemperature shock precursor as it breaks through the surface of the presupernova star. The total energy released is predicted to be 1048 ergs, comparable to that which is consistent with the observed pulses from supernovae Mpc distant. Subject headings: gamma rays - supernovae