ИСТИНА

We consider a new concept of gamma-ray telescope called MAST for the energy range of 100 MeV – 1 TeV [1]. An era of the next-generation heavy rockets has begun (e.g., the Falcon Heavy rocket [2]), so it becomes possible to lift a payload as heavy as 63.8 t to the low Earth orbit and about 40 t to a medium (∼500 km) circular Earth orbit. Therefore we consider it reasonable to propose a concept of a liquid argon heavy time projection chamber with the total sensitive mass about 36 t as a new- generation space gamma-ray telescope for the 100 MeV ‒ 1 TeV energy range. We estimate the basic characteristics of the MAST telescope and show that its angular resolution is 3-10 times better than the Fermi-LAT one (depending on the energy) [3], and its differential sensitivity is even more than 10 times better than the Fermi-LAT one. A simplified energy reconstruction method yields the energy resolution about 20% at 100 MeV and between 6% and 10% for the 10 GeV ‒ 1 TeV energy range. Thus the MAST instrument may be a promising tool in a wide range of tasks, including the search for signals of dark matter annihilation/decay, precision constraints on extragalactic gamma-ray propagation models, studies of the extragalactic background light, the search for gamma-ray counterparts of IceCube neutrinos and LIGO/VIRGO. This work was supported by the Russian Science Foundation (RSF) (project No 18- 72-00083). References: 1 T. Dzhatdoev, E. Podlesnyi, Astroparticle Physics, 112, 1 (2019) (arXiv:1902.01491) 2 https://www.spacex.com/falcon-heavy 3 W. B. Atwood et al., ApJ, 697, 1071 (2009)