Observations of Gamma-ray Bursts with VERITAS and Whipple

TL;DR

This paper reports on observations of gamma-ray bursts using VERITAS and Whipple telescopes from 2005 to 2007, motivated by recent discoveries of X-ray flares and predictions of very-high-energy emission, but no definitive detections have been made.

Contribution

It details the implementation of rapid follow-up VHE observations of GRBs and reports observational results from 2005 to 2007.

Findings

No definitive VHE emission detections from GRBs.

Established rapid response procedures for GRB follow-up.

Collected data sets for future analysis.

Abstract

Many authors have predicted very-high-energy (VHE; E > 100 GeV) emission from gamma-ray bursts (GRBs) both during the prompt phase and during the multi-component afterglow. To date, however, there has been no definitive detection of such emission. Recently, the Swift Satellite made the exciting discovery that almost 50% of GRBs are accompanied by one or more X-ray flares, which are found to occur from several seconds to many hours after the prompt emission. The discovery of this phenomenon and the many predictions that VHE emission should accompany these flares increases the already strong motivation for making immediate follow-up VHE observations of GRBs. Observations of GRBs have high priority at VERITAS, preempting any observations that may be in progress. GRB alerts are received from the GCN via a socket connection. This is interfaced to the VERITAS Tracking Software to minimize the time between a notification arriving and the telescope being slewed to the GRB. We report here on GRB observations with VERITAS and with the Whipple Telescope from 2005 through 2007.