ИСТИНА

We propose a new concept of gamma-ray telescope called MAST [1] (an abbreviation from “massive Argon space telescope”) for the energy range of 100 MeV – 1 TeV based on the liquid Argon time projection chamber (LAr TPC) technique. The LAr TPC technique has many important advantages, including simplicity, scalability and cost-effectiveness, at the same time allowing to obtain good spatial (and hence angular) resolution. Using last-generation rockets such as Falcon Heavy [2], it is possible to launch a payload with the mass up to 30–40 t to a medium (∼500 km) circular Earth orbit, for the first time allowing to reveal the potential of the LAr TPC technique in gamma-ray astronomy. We estimate the basic parameters of the MAST telescope and show that the achievable angular resolution is 3-10 times better than the Fermi-LAT one [3] depending on the energy, and the differential sensitivity is about one order of magnitude better than the Fermi-LAT one. The energy resolution of the MAST telescope is comparable to the Fermi-LAT one (about 20 % at 100 MeV and between 6 % and 10 % for the 10 GeV – 1 TeV energy range). Such an instrument with an effective energy threshold ~100 MeV, very good sensitivity, and reasonable energy resolution would have a great potential in a wide range of astrophysical tasks, including observations of active galactic nuclei, the search for gamma-ray counterparts of IceCube astrophysical neutrinos, the studies of the extragalactic background light, extragalactic magnetic field and extragalactic gamma-ray background, and dark matter searches. The details of our calculations are available in [1]. 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)