On the Counter-jet Emission in GRB Afterglows

TL;DR

This paper studies the evolution and emission of receding jets in gamma-ray burst afterglows, revealing that their signals are weak and affected by synchrotron self-absorption, which influences their detectability in radio observations.

Contribution

It provides detailed numerical analysis of the receding jet emission in GRB afterglows, highlighting its weak nature and the impact of synchrotron self-absorption on observational features.

Findings

Receding jet emission appears as a late-time radio plateau.

Synchrotron self-absorption significantly affects the peak time.

Receding jets are generally very weak in afterglow signals.

Abstract

We investigate the dynamical evolution of double-sided jets and present detailed numerical studies on the emission from the receding jet of gamma-ray bursts. It is found that the receding jet emission is generally very weak and only manifests as a plateau in the late time radio afterglow light curves. Additionally, we find that the effect of synchrotron self-absorption can influence the peak time of the receding jet emission significantly.