Muon Identification with VERITAS using the Hough Transform

Abstract

Imaging atmospheric Cherenkov telescope (IACT) arrays such as VERITAS are used for ground-based very high-energy gamma-ray astronomy. This is accomplished by the detection and analysis of the Cherenkov light produced by gamma-ray-initiated atmospheric air showers. IACTs also detect the Cherenkov light emitted by individual muons. Identification of these muons is useful because their Cherenkov light can be used to calibrate the telescopes. Muons create characteristic annular patterns in the cameras of IACTs, which may be identified using parametrization algorithms. One such algorithm, the Hough transform, has been successfully used to identify muons in VERITAS data. Details of this technique are presented here, including results regarding its effectiveness