On the multiwavelength emission from Gamma Ray Burst afterglows

TL;DR

This paper models the multiwavelength emission of Gamma Ray Burst afterglows using a one-zone SSC framework, analyzing how electron injection, cooling, and environmental factors influence observed spectra over time.

Contribution

It introduces a comprehensive numerical and analytical approach to modeling GRB afterglows considering SSC losses and varying magnetic fields, extending previous synchrotron-only models.

Findings

SSC losses dominate in high electron injection or density scenarios.

Solutions deviate significantly from standard synchrotron models under certain conditions.

The model explains multiwavelength spectra evolution in GRB afterglows.

Abstract

Aims: Drawing an analogy with Active Galactic Nuclei, we investigate the one-zone SSC model of Gamma Ray Bursts afterglows in the presence of electron injection and cooling both by synchrotron and SSC losses. Methods: We solve the spatially averaged kinetic equations which describe the simultaneous evolution of particles and photons, obtaining the multi-wavelength spectrum as a function of time. We back up our numerical calculations with analytical solutions of the equations using various profiles of the magnetic field evolution under certain simplifying assumptions. Results: We apply the model to the afterglow evolution of GRBs in a uniform density environment and examine the impact various parameters have on the multiwavelength spectra. We find that in cases where the electron injection and/or the ambient density is high, the losses are dominated by SSC and the solutions depart significantly from the ones derived in the synchrotron standard cases.