TP-13

Thomson Depth Evolution of GRB and Afterglow and its Observable Manifestations

Edison Liang, Markus Boettcher (Rice University) and Charles Dermer (NRL)

We study the evolution of the Thomson depth of the shock front in relativistic explosion scenarios of gamma-ray bursts. We follow the evolution from first principles, starting with the free-expansion or fireball phase, through the blast wave or snowplow phase, into the radiative phase. We study the effects of such evolution on the observables of the GRB and its afterglow, and discuss observational tests with BATSE data.