Bulk relativistic motion in gamma-ray bursts

Abstract

It is shown here that any model for gamma-ray bursts in which the gamma-rays in the source are isotropic in a frame moving relativistically with respect to external observers has several advantageous traits: hard photons can escape more easily, the radiated energy per burst is reduced, and stellar back-heating is virtually eliminated. In addition, several other features of gamma-ray burst phenomenology must be reinterpreted: the burst source density, or alternatively, the recurrence time per source, is altered, and the physical interpretation of spectral features may also be substantially changed.