Study of shock wave dynamics produced by interaction of a fireball with the surrounding medium to it, to explain the x-ray afterglow of Gamma Ray Burst-GRBs

TL;DR

This paper develops an astrophysical hydrodynamic and radiative model to explain the x-ray afterglow of Gamma Ray Bursts, specifically comparing it with observational data from GRB 050525.

Contribution

It introduces a combined hydrodynamic and radiative model for GRB afterglows and validates it against observational data from GRB 050525.

Findings

Blast wave radius increases as t^{1/4}

Lorentz gamma factor decreases significantly over time

Radiation flux follows a t^{-1} decay, matching observed afterglow slopes

Abstract

The Gamma-Ray Bursts - GRBs are one of the most energetic astronomical events in the universe that have not yet an adequate explanation of what kind of mechanism is carried out. This question motivates the astronomical community to do radiation measurements associated with the GRBs. They also are doing physical models to explain the temporal behavior of these observational results. The community are looking for an appropriate explanation of GRBs origin. This thesis presents an astrophysical model that includes an hydrodynamic and radiative aspects. This model studies the temporal evolution of a wave carries an expansive ultra-relativistic adiabatic fluid. Additionally, this thesis present a comparison between model with GRB 050525 observational behavior. It is found that the blast wave radius R shows an increase in the time: R \approx t^{1/4}, the Lorentz gamma factor of charged particles that are in ultra-relativistic fluid decreases significantly over time and the theoretical flow of radiation: F_{\nu} \approx t^{-\beta} with {\beta} around 1 fits very well with the two slopes of the x-ray afterglow light curve of GRB 050525.