Optimal gamma-ray selections for monochromatic line searches with DAMPE

Abstract

The DArk Matter Particle Explorer (DAMPE) is a space high-energy cosmic-ray detector covering a wide energy band with a high energy resolution. One of the key scientific goals of DAMPE is to carry out indirect detection of dark matter by searching for high-energy gamma-ray line structure. To promote the sensitivity of gamma-ray line search with DAMPE, it is crucial to improve the acceptance and energy resolution of gamma-ray photons. In this paper, we quantitatively prove that the photon sample with the largest ratio of acceptance to energy resolution is optimal for line search. We therefore develop a line-search sample specifically optimized for the line search.Meanwhile, in order to increase the statistics, we also selected the so called BGO-only photons that convert into e + e − pairs only in the BGO calorimeter. The standard, the line-search, and the BGO-only photon samples are then tested for line search individually and collectively. The results show that a significantly improved limit could be obtained from an appropriate combination of the date sets, and the increase is about 20% for the highest case compared with using the standard sample only.

On a Possible Origin of the Gamma-ray Excess around the Galactic Center

“…Our most recent simulations of GAMMA-400 energy resolution showed that realistically we can expect this sensitivity to be comparable to that of Fermi-LAT in the energy range ∼(0.1-100) GeV. At the same time DAMPE has comparable sensitivity too [30]. Hence the combined (stacked) data analysis from all three telescopes will potentially allow to significantly extend the range of probed diphoton annihilation cross sections.…”

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

“…However our most recent simulations showed that the sensitivity presented in (Egorov et al, 2020) tends towards slightly optimistic siderealistically we would expect our sensitivity to be comparable with that of Fermi-LAT after 12-15 years of its operation. At the same time DAMPE has comparable sensitivity too (Zun-Lei Xu et al, 2021). Hence, it can be possible in the future to stack together the data from all three telescopes and significantly extend the sensitivity to narrow lines by such joint data analysis.…”