Gamma-ray burst afterglows from trans-relativistic blast waves

TL;DR

This paper investigates the intermediate trans-relativistic phase of gamma-ray burst afterglows by combining advanced hydrodynamics simulations with detailed radiation modeling, providing new insights into their evolution.

Contribution

It introduces a novel approach linking microphysics parametrization with high-resolution hydrodynamics to study gamma-ray burst afterglows in the trans-relativistic regime.

Findings

First detailed spectra and light curves in the trans-relativistic phase

Enhanced understanding of shock microphysics effects

Improved modeling of afterglow evolution

Abstract

We present a study of the intermediate regime between ultra-relativistic and nonrelativistic flow for gamma-ray burst afterglows. The hydrodynamics of spherically symmetric blast waves is numerically calculated using the AMRVAC adaptive mesh refinement code. Spectra and light curves are calculated using a separate radiation code that, for the first time, links a parametrisation of the microphysics of shock acceleration, synchrotron self-absorption and electron cooling to a high-performance hydrodynamics simulation.