Evidence for a Galactic Origin of Very Short Gamma Ray Bursts and Primordial Black Hole Sources

Abstract

We systematically study the shortest time duration gamma ray bursts and find unique features that are best interpreted as sources of a galactic origin. There is a significant angular asymmetry and the V/Vmax distribution provides evidence for a homogenous or Euclidean source distribution. We eview the arguments that primordial black hole evaporation can give such GRBs. The rate of events is consistent with a PBH origin if we assume on enhanced local density, as are the other distributions. We suggest further tests of this hypothesis.