Hard Electron Energy Distribution in the Relativistic Shocks of GRB Afterglows

TL;DR

This paper explores the possibility of hard electron energy distributions in relativistic shocks of GRB afterglows, modifying existing models to better match observations and analyzing their impact on emission spectra.

Contribution

It introduces modifications to the standard afterglow model to incorporate hard electron energy spectra and applies this to specific GRB afterglows for parameter estimation.

Findings

Hard electron spectra can significantly alter afterglow emission predictions.

Modeling GRB010222 and GRB020813 with hard spectra provides better fits to observed data.

The study suggests electron acceleration mechanisms may produce harder energy distributions than previously assumed.

Abstract

Particle acceleration in relativistic shocks is not a very well understood subject. Owing to that difficulty, radiation spectra from relativistic shocks, such as those in GRB afterglows, have been often modelled by making assumptions about the underlying electron distribution. One such assumption is a relatively soft distribution of the particle energy, which need not be true always, as is obvious from observations of several GRB afterglows. In this paper, we describe modifications to the afterglow standard model to accommodate energy spectra which are `hard'. We calculate the overall evolution of the synchrotron and compton flux arising from such a distribution. We also model two afterglows, GRB010222 and GRB020813, under this assumption and estimate the physical parameters.