Gamma rays from the neutralino dark matter annihilations in the Milky Way substructures

High resolution simulations reveal that in the cold dark matter scenario the structures form hierarchically and a large number of substructures survive in the galactic halos. The substructures can be probed if they emit gamma rays via dark matter annihilation. We calculated the gamma ray fluxes from the dark matter annihilations in the substructures of our Galaxy within the frame of the minimal supersymmetric extension of the standard model. The uncertainties of the prediction from both the low energy supersymmetry and especially from the density profiles of dark matter in the substructures are carefully investigated. The cumulative number of substructures emitting gamma rays above any given flux is calculated. Detectability of the gamma rays from the substructures is discussed. We propose the viability to detect these signals through the ground large field of view detectors. (c) 2006 Elsevier B.V. All rights reserved.