Hydrodynamics of a Relativistic Fireball: The Complete Evolution
Abstract
We study numerically the evolution of an adiabatic relativistic fireball expanding into a cold uniform medium. We follow the stages of initial free expansion and acceleration, coasting, and then deceleration and slowing down to a nonrelativistic velocity. We compare the numerical results with simplified analytical estimates. We show that the relativistic selfsimilar BlandfordMcKee solution describes well the relativistic deceleration epoch. It is an excellent approximation throughout the relativistic deceleration stage, down to γ~5, and a reasonable approximation even down to γ~2, though the solution is rigorous only for γ>>1. We examine the transition into the BlandfordMcKee solution and the transition from the solution to the nonrelativistic selfsimilar SedovTaylor solution. These simulations demonstrate the attractive nature of the BlandfordMcKee solution and its stability to radial perturbations.
 Publication:

The Astrophysical Journal
 Pub Date:
 March 1999
 DOI:
 10.1086/306868
 arXiv:
 arXiv:astroph/9803217
 Bibcode:
 1999ApJ...513..669K
 Keywords:

 GAMMA RAYS: BURSTS;
 HYDRODYNAMICS;
 RELATIVITY;
 SHOCK WAVES;
 Gamma Rays: Bursts;
 Hydrodynamics;
 Relativity;
 Shock Waves;
 Astrophysics
 EPrint:
 Submitted to ApJ, 35 pages, latex, 14 figures