Constraints on light decaying dark matter candidates from 16 yr of INTEGRAL/SPI observations

Abstract

We apply the recently developed analysis of 16 yr of INTEGRAL/SPI data including a dark matter spatial template to derive bounds on dark matter candidates lighter than weakly interacting massive particles (like sterile neutrinos or axion-like particles) decaying into line or continuum electromagnetic final state channels. The bounds obtained are the strongest to date for dark matter masses between ∼60 keV and ∼16 MeV experiencing two-body decays producing photon lines.