Dark matter annihilation in the local group

Under the hypothesis of a dark matter composed by supersymmetric particles such as neutralinos, we investigate the possibility that their annihilation in the halos of nearby galaxies could produce detectable fluxes of gamma photons. Expected fluxes depend on several, poorly known quantities such as the density profiles of dark matter halos, the existence and prominence of central density cusps and the presence of a population of subhalos. We find that, for all reasonable choices of dark matter halo models, the intensity of the gamma-ray flux from some of the nearest extragalactic objects, such as M31, is comparable to or higher than the diffuse galactic foreground. We show that next generation ground-based experiments could have the sensitivity to reveal such fluxes which could help us to unveil the nature of dark matter particles