GRB spectral parameters within the fireball model

TL;DR

This paper models gamma-ray burst spectra within the fireball framework, showing that diffusive synchrotron radiation in random magnetic fields aligns with observed spectral parameters and constrains physical conditions.

Contribution

It introduces a comprehensive modeling approach for GRB spectra based on diffusive synchrotron radiation in the fireball model, linking theory with observations.

Findings

DSR mechanism matches observed Band parameter distributions

Model constrains GRB physical parameters

Random magnetic fields produce consistent spectral features

Abstract

Fireball model of the GRBs predicts generation of numerous internal shocks, which then efficiently accelerate charged particles and generate magnetic and electric fields. These fields are produced in the form of relatively small-scale stochastic ensembles of waves, thus, the accelerated particles diffuse in space due to interaction with the random waves and so emit so called Diffusive Synchrotron Radiation (DSR) in contrast to standard synchrotron radiation they would produce in a large-scale regular magnetic fields. In this paper we present first results of comprehensive modeling of the GRB spectral parameters within the fireball/internal shock concept. We have found that the non-perturbative DSR emission mechanism in a strong random magnetic field is consistent with observed distributions of the Band parameters and also with cross-correlations between them; this analysis allowed to restrict GRB physical parameters from the requirement of consistency between the model and observed distributions.