Constraints on WIMP annihilation for contracted dark matter in the inner Galaxy with gamma-rays

Abstract

Detection of gamma rays and cosmic rays from the annihilation or decay of dark matter particles is a promising method for identifying dark matter, understanding its intrinsic properties, and mapping its distribution in the universe. Based on N-body simulations the largest γ-ray signal from DM annihilation is expected from the centre of the Galaxy. In the same region a large γ-ray background is produced by bright discrete sources and the cosmic-rays interacting with the interstellar gas and the photons fields but the DM-induced gamma-ray emission is expected to be so large there that the search is still worthwhile. We derive constraints on parameters of generic dark matter candidates by comparing theoretical predictions with the gamma-ray emission observed by the Fermi-LAT from the region around the Galactic Center. Our analysis is conservative since it simply requires that the expected dark matter signal does not exceed the observed emission.