Results from the first one and a half years of the HAWC GRB program

TL;DR

This paper reports on the initial 1.5 years of HAWC's efforts to detect TeV gamma-ray emissions from gamma-ray bursts, utilizing its wide field of view and high uptime to improve understanding of GRB origins and fundamental physics.

Contribution

It presents the first results of HAWC's GRB search methods, including all-sky and follow-up observations, after one and a half years of data collection.

Findings

Initial constraints on TeV emission from GRBs

Effective all-sky and follow-up search strategies implemented

Potential for future discoveries to inform astrophysics and fundamental physics

Abstract

The High-Altitude Water Cherenkov (HAWC) Observatory is a ground-based TeV gamma-ray observatory in the state of Puebla, Mexico at an altitude of 4100 m above sea level. Its $\sim$22,000 m$^2$ instrumented area, wide field of view (2 sr), and $>$95% uptime make it an ideal instrument for discovering gamma-ray burst (GRB) emission at $>$100 GeV. Such a discovery would provide key information about the origins of prompt GRB emission as well as constraints on EBL models and the violation of Lorentz invariance. We present here the results of our current GRB search methods, which include an all-sky search as well as fast follow-ups of GRBs reported by satellites, after one and a half years of data with the full HAWC detector.