High-energy emission from Gamma-Ray Bursts

TL;DR

This review discusses the spectral and temporal properties of high-energy gamma-ray bursts observed by Fermi-LAT, evaluates current theoretical models, and explores future prospects for very-high-energy observations to enhance understanding.

Contribution

It provides a comprehensive summary of observational properties, reviews existing models, and discusses future observational opportunities at very-high energies.

Findings

Fermi-LAT has significantly improved GRB high-energy data quality.

Current models face challenges explaining all observed properties.

Future ground-based detectors may observe GRBs at very-high energies.

Abstract

The number of Gamma-Ray Bursts (GRBs) detected at high energies ($\sim\,0.1-100$ GeV) has seen a rapid increase over the last decade, thanks to observations from the Fermi-Large Area Telescope. The improved statistics and quality of data resulted in a better characterisation of the high-energy emission properties and in stronger constraints on theoretical models. In spite of the many achievements and progresses, several observational properties still represent a challenge for theoretical models, revealing how our understanding is far from being complete. This paper reviews the main spectral and temporal properties of $\sim\,0.1-100$ GeV emission from GRBs and summarises the most promising theoretical models proposed to interpret the observations. Since a boost for the understanding of GeV radiation might come from observations at even higher energies, the present status and future prospects for observations at very-high energies (above $\sim$ 100 GeV) are also discussed. The improved sensitivity of upcoming facilities, coupled to theoretical predictions, supports the concrete possibility for future ground GRB detections in the high/very-high energy domain.