Insights into the properties of GRBs with TeV emission

TL;DR

This paper explores the environments and prompt emission characteristics of GRBs with TeV emission, finding no distinct environmental or emission features that differentiate them from the general GRB population.

Contribution

It provides the first comparative analysis of VHE-detected GRB environments and employs machine learning to analyze prompt emission light curves, revealing no unique features.

Findings

VHE GRBs have similar environments to typical GRBs.

VHE GRBs are distributed across emission feature space, not forming distinct clusters.

VHE detection appears observational rather than due to intrinsic differences.

Abstract

This study investigates the environments and characteristics of Gamma-Ray Bursts (GRBs) exhibiting very high energy (VHE) emission. Recent detections of VHE emission, up to TeV energies, challenge synchrotron-only emission models and particle acceleration concepts in GRBs. Until now, only a handful of GRBs have been detected in the VHE range. We compare the number densities of the circumburst medium of VHE-detected GRBs to check if the environment impacts the VHE emission. This shows that these GRBs have environments similar to the larger population of GRBs. We employ machine learning algorithms to create two-dimensional embeddings of GRB prompt emission light curves from the {\it Swift}-BAT catalog. VHE-detected GRBs are located across the map, indicating that VHE emission does not favour any particular cluster. These findings indicate that VHE-detected GRBs do not show any peculiar characteristics other than the observational detection of VHE photons. Future detections will increase the sample size required for a rigorous understanding of the origin of VHE emission in GRBs.