GAMMA-400 Gamma-Ray Observations in the GeV and TeV Energy Range

Abstract

The future space-based GAMMA-400 $\gamma$-ray telescope will operate onboard the Russian astrophysical observatory in a highly elliptic orbit during 7 years. Observing $\gamma$-ray sources from Galactic plane, $\gamma$-ray bursts, $\gamma$-ray diffuse emission, $\gamma$ rays from the Sun, and $\gamma$ rays from dark matter particles will be performed uninterruptedly for a long time (${\sim}$100 days) in point-source mode in contrast to scanning mode for Fermi-LAT and other space- and ground-based instruments. GAMMA-400 will measure $\gamma$ rays in the energy range from ${\sim}$20 MeV to several TeV units, have the unprecedented angular (${\sim}0.01^{\circ}$ at $E_{\gamma}=100$ GeV) and energy (${\sim}2{\%}$ at $E_{\gamma}=100$ GeV) resolutions better than for Fermi-LAT, as well as ground-based $\gamma$-ray facilities, by a factor of 5–10, and perfectly separate $\gamma$ rays from cosmic-ray background.