Multi-messenger detection prospects of gamma-ray burst afterglows with optical jumps

TL;DR

This paper explores the potential for detecting high-energy neutrinos from gamma-ray burst afterglows with optical jumps, suggesting that such detections could reveal the physical mechanisms behind these optical features.

Contribution

It introduces a model linking optical jumps in GRB afterglows to increased neutrino emission and assesses detection prospects with current and future observatories.

Findings

Neutrino emission can increase by an order of magnitude during optical jumps.

Detection of neutrinos could constrain properties of the circumburst medium.

Neutrino observations may reveal the mechanisms behind optical jumps.

Abstract

Some afterglow light curves of gamma-ray bursts (GRBs) exhibit very complex temporal and spectral features, such as a sudden intensity jump about one hour after the prompt emission in the optical band. We assume that this feature is due to the late collision of two relativistic shells and investigate the corresponding high-energy neutrino emission within a multi-messenger framework, while contrasting our findings with the ones from the classic afterglow model. For a constant density circumburst medium, the total number of emitted neutrinos can increase by about an order of magnitude when an optical jump occurs with respect to the self-similar afterglow scenario. By exploring the detection prospects with the IceCube Neutrino Observatory and future radio arrays such as IceCube-Gen2 radio, RNO-G and GRAND200k, as well as the POEMMA spacecraft, we conclude that the detection of neutrinos with IceCube-Gen2 radio could enable us to constrain the fraction of GRB afterglows with a jump as well as the properties of the circumburst medium. We also investigate the neutrino signal expected for the afterglows of GRB 100621A and a GRB 130427A-like burst with an optical jump. The detection of neutrinos from GRB afterglows could be crucial to explore the yet-to-be unveiled mechanism powering the optical jumps.