Constraints on annihilating dark matter in the Omega Centauri cluster

Abstract

Recent gamma-ray and radio studies have obtained some stringent constraints on annihilating dark matter properties. However, only a few studies have focused on using x-ray data to constrain annihilating dark matter. In this article, we perform the x-ray analysis of annihilating dark matter using the data of the Omega Centauri cluster. If dark matter is the correct interpretation of the nonluminous mass component derived in the Omega Centauri cluster, the conservative lower limits of thermal dark matter mass annihilating via the ${\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$, $b\overline{b}$, and ${W}^{+}{W}^{\ensuremath{-}}$ channels can be significantly improved to 104(43) GeV, 650 (167) GeV, and 480(137) GeV, respectively, assuming the diffusion coefficient ${D}_{0}\ensuremath{\le}{10}^{26}({10}^{27})\text{ }\text{ }{\mathrm{cm}}^{2}/\mathrm{s}$. These constraints can safely rule out the recent claims of dark matter interpretation of the gamma-ray excess and antiproton excess seen in our Galaxy. Generally speaking, the conservative lower limits obtained for nonleptophilic annihilation channels are much more stringent than that obtained by gamma-ray analysis of nearby dwarf galaxies. We anticipate that this would open a new window for constraining annihilating dark matter.