Monte Carlo studies of the VERITAS array of Cherenkov telescopes

TL;DR

This paper presents detailed Monte Carlo simulations of the VERITAS Cherenkov telescope array, demonstrating accurate predictions of its response to cosmic rays and gamma-rays, and confirming its sensitivity and energy threshold.

Contribution

It provides comprehensive Monte Carlo simulation results that validate the VERITAS array's performance and sensitivity in gamma-ray detection.

Findings

Simulation results agree with observational data

Energy threshold is about 150 GeV after cuts

Detection rate for Crab Nebula is 7.5 gamma/min

Abstract

VERITAS is a system of four imaging Cherenkov telescopes located at the Fred Lawrence Whipple Observatory in southern Arizona. We present here results of detailed Monte Carlo simulations of the array response to extensive air showers. Cherenkov image and shower parameter distributions are calculated and show good agreement with distributions obtained from observations of background cosmic rays and high-energy gamma-rays. Cosmic-ray and gamma-ray rates are accurately predicted by the simulations. The energy threshold of the 3-telescope system is about 150 GeV after gamma-hadron separation cuts; the detection rate after gamma-selection cuts for the Crab Nebula is 7.5 gamma's/min. The three-telescope system is able to detect a source with a flux equivalent to 10% of the Crab Nebula flux in 1.2 h of observations (5 sigma detection).