Performance of the ASTRI Mini-Array with different levels of the Night Sky Background

Abstract

The ASTRI Mini-Array is an array of nine small-sized (4-m diameter) and large field of view (∼10 • ) imaging atmospheric Cherenkov telescopes under deployment at the Observatorio del Teide (Tenerife, Spain). The system is sensitive to 𝛾-ray radiation in the energy range 1 ÷ 200 TeV. The telescopes are characterized by a dual-mirror optical system and equipped with silicon photo-multiplier cameras. These sensors can be operated under relatively high levels of night-sky background, thus allowing us to extend the duty cycle of Cherenkov observations beyond the "dark" regime alone. In order to assess the performance of the system with different night-sky brightness conditions, a study of the intensity and spectral shape of the illumination at the Teide Observatory site as a function of the array pointing direction and of the lunar phase has been carried out. Then, dedicated Monte Carlo simulations have been generated with a set of increasing brightness levels and subsequently reduced with A-SciSoft (ASTRI Scientific Software), the official scientific software package of the ASTRI Project. In this contribution, we present the performance of the ASTRI Mini-Array achieved with the aforementioned MC simulations, discussing the implications of our finding on the duty cycle of the system and its scientific potentialities.

Science with the ASTRI Mini-Array: From Experiment to Open Observatory

“…A single pointing will allow us to investigate the Galactic Center or the Cygnus regions. In these regions, we can accumulate several hundreds of hours by also including the epochs of moderate Moon condition [32]. This is crucial to investigate both the (energy-dependent) morphology of the sources in these regions and their possible variability on a long time scale.…”