Direct conversion of the flux of kinetic energy into radiation in   gamma-ray burst
  The time evolution of a Gamma-ray burst (GRB) is associated with the evolution of a supernova remnant (SNR). The time evolution of the flux of a GRB is modeled introducing a law for the density of the medium in the advancing layer. The adopted radiative model for the GRB in the various e.m. frequencies is synchrotron emission. The X-ray ring which appears a few hours after a GRB is simulated. 
L. Zaninetti
astro-ph.HE