The ASTRI Mini-Array is an international project led by the Italian National Institute for Astrophysics (INAF) aimed at the construction and operation of an array of nine Imaging Atmospheric Cherenkov Telescopes (IACTs) at the Observatorio del Teide in Tenerife (Spain). The project is designed to detect very high-energy gamma rays up to the multi-TeV energy scale. The telescopes design, based on the Schwarzschild-Couder two mirror configuration and Silicon Photomultipliers sensors, leads to a very wide field of view of 10.5 degrees which allows to cover a large ground surface area with an average inter-telescope distance of about 160 m. Upon completion, it will be for some time the largest IACT array in operation below 2,500m a.s.l. both in terms of number of telescopes and of ground surface area, with the primary goal of investigating gamma-ray emission from celestial sources. The ASTRI Mini-Array design and expected performance are based on the stereoscopic technique, i.e. the detection of the same atmospheric shower event with two or more telescopes: therefore the correct identification of the single-telescope triggers participating to the same stereo event is of paramount importance. This strong requirement must meet the need to observe muon events with each single-telescope to allow for calibrations with adequate precision. In the ASTRI Mini-Array operation concept, all the single-telescope events are acquired independently and stored for off-line processing. The Stereo Event Builder (SEB) software system is the part of the off-line reconstruction chain that is responsible for identifying single and stereo Cherenkov events. The SEB constraints, design, and expected performance are described in this article.
|