Design studies for the future 50 GeV arrays of imaging air Čerenkov telescopes

Abstract

Arrays of imaging air Čerenkov telescopes (IACTs) like VERITAS, HESS have been recently proposed as the instruments of the next generation for ground based very high energy γ-ray astronomy invading into 50–100 GeV energy range. Here we present results of design studies for the future IACT arrays which have been performed by means of Monte Carlo simulations. We studied different trigger strategies, abilities of cosmic ray rejection for arrays of 4 and 16 telescopes with 10 m reflectors, equipped with cameras comprising 271 and 721 pixels of 0.25° and 0.15°, respectively. The comparative analysis of the performance of such telescope arrays has been done for both camera options, providing almost the same field of view of ∼4.3°. An important issue is the choice of the optimum spacing between the telescopes in such an array. In order to maximize the signal-to-noise ratio in observations at the small zenith angles of ∼20° as well as at large zenith angles of ∼60°, different arrangements of IACT array have been examined. Finally, we present a major recommendations regarding the optimum configuration.