An RMHD study of transition between prompt and afterglow GRB phases

TL;DR

This paper uses relativistic magnetohydrodynamic simulations to investigate the transition from prompt to afterglow phases in gamma-ray bursts, focusing on the effects of ejecta magnetization on shock formation and emission.

Contribution

It introduces a novel scheme for including non-thermal processes in RMHD simulations to study GRB afterglow phases.

Findings

Magnetization influences the formation of reverse shocks.

Energy transfer timescales depend on ejecta magnetization.

Simulated light curves show distinct features based on magnetization levels.

Abstract

We study the afterglow phases of a GRB through relativistic magnetohydrodynamic simulations. The evolution of a relativistic shell propagating into a homogeneous external medium is followed. We focus on the effect of the magnetization of the ejecta on the initial phases of the ejecta-external medium interaction. In particular we are studying the condition for the existence of a reverse shock into the ejecta, the timescale for the transfer of the energy from the shell to the shocked medium and the resulting multiwavelength light curves. To this end, we have developed a novel scheme to include non-thermal processeses which is coupled to the relativistic magnetohydrodynamic code MRGENESIS in order to compute the non-thermal synchrotron radiation.