High-energy gamma- and cosmic-ray observations with future space-based GAMMA-400 gamma-ray telescope

Abstract

The future space-based GAMMA-400 gamma-ray telescope will be installed on the Navigator platform of the Russian Astrophysical Observatory. A highly elliptical orbit will provide observations for 7-10 years of many regions of the celestial sphere continuously for a long time (~ 100 days). GAMMA-400 will measure gamma-ray fluxes in the energy range from ~ 20 MeV to several TeV and electron + positron fluxes up to ~ 20 TeV. GAMMA-400 will have an excellent separation of gamma rays from the background of cosmic rays and electrons + positrons from protons and an unprecedented angular (~ 0.01° at Eγ = 100 GeV) and energy (~ 1% at Eγ = 100 GeV) resolutions better than for Fermi-LAT, as well as ground-based facilities, by a factor of 5-10. Observations of GAMMA-400 will provide new fundamental data on discrete sources and spectra of gamma-ray emission and electrons + positrons, as well as the nature of dark matter.

Indirect detection prospects for d*(2380) dark matter

“…Our results in the Coma case already exceed the model-translated limits from [40,41] by around 2 orders of magnitude. To supplement the higher energy measurements we have also considered the sensitivity projections of the GAMMA-400 telescope [59,60] for 4 years of exposure time. This curve indicates that the Coma cluster can be probed for d * decays to a level of Γ d * ∼ 10 −26 s −1 at the 95% confidence interval, though contamination by other emissions will likely limit this potential.…”

“…The most optimistic observation case is from our results is the Milky-Way galactic centre which produces limits from gammaray fluxes similar to model-independent limits from [40] limit around two orders of magnitude in excess of the age of the universe. If not for the limited energy range of the Reticulum II gamma-ray data it is likely that the strongest extragalactic environment for these constraints is dwarf galaxies (particularly with gamma-ray measurements from instruments like GAMMA-400 [59][60][61] or perhaps millimetre telescopes). Radio limits are weak across the board due to the very low energy of the synchrotron peak as a consequence of the small d * mass.…”

Capabilities of the GAMMA-400 gamma-ray telescope to detect gamma-ray bursts from lateral directions

“…The total calorimeter thickness for vertical incidence direction is 18 X 0 or ~0.9 λ 0 (λ 0 is the nuclear interaction length). Using the deep calorimeter allows us to extend the energy range up to several TeV for gamma rays and to reach an energy resolution ~2% at 100 GeV [7]. The total calorimeter thickness for lateral detection of particles is ~42 X 0 or ~1.95 λ 0 , providing the possibility to measure intensities of high-energy electrons and gamma rays up to ~10 TeV.…”

“…The structure of SciFi converter-tracker with analog readout, ToF system with large flight distance (500 mm), and additional layer of SciFi coordinate detector in CC1 allows us to obtain unprecedented angular resolution: ∼0.01° at E γ = 100 GeV [7]. To detect gamma rays from lateral directions the information from CC2, S3, S4 and LD detectors is used.…”

“…The main experimental goal of GAMMA-400 gamma-ray telescope is to measure gamma-ray fluxes in the energy range from ~20 MeV to ~1 TeV with high angular and energy resolutions. The main top-down aperture of the instrument is about ±45° [7].…”