Cosmophysical Research with GAMMA-400

The GAMMA-400 gamma-ray telescope is the successor of Soviet and Russian gamma-ray telescopes. GAMMA-400 is being developed for cosmophysical research in accordance with the Russian Federal Space Program 2016–2025. The GAMMA-400 experiment will be implemented aboard the Russian astrophysical space observatory in a highly elliptic orbit during 7 years to provide new data on gamma-ray emission mainly from the Galactic plane, Galactic Center, the Sun and cosmic-ray electron + positron fluxes. The main mode of observations will be the continuous point-source mode with the duration of up to ∼ 100 days. The GAMMA-400 gamma-ray telescope will study high-energy gamma-ray emission up to several TeV and cosmic-ray electrons + positrons up to 20 TeV. GAMMA-400 will have the never-achieved angular resolution, the high-energy and time resolutions, as well as very good separation efficiency of gamma rays from cosmic-ray background and of electrons + positrons from protons. The distinctive features of GAMMA-400 are the excellent angular resolution of ∼0.01^∘ at E_γ=100 GeV that exceeds resolutions of the space-based and ground-based gamma-ray telescopes by a factor of 5–10, as well as high-energy resolution of ∼2% at E_γ=100 GeV. GAMMA-400 studies can discover gamma-ray emission from annihilation or decay of dark matter particles, identify many unassociated discrete sources, explore the structure of extended sources, search for gamma-ray bursts and solar gamma-ray flares, improve the data on cosmic-ray electron + positron spectra for energies of >50 GeV.