Investigating halo substructures with annual modulation signature

Abstract

Galaxy hierarchical formation theories, numerical simulations, the discovery of the Sagittarius Dwarf Elliptical Galaxy (SagDEG) in 1994 and more recent investigations suggest that the dark halo of the Milky Way can have a rich phenomenology containing non thermalized substructures. In the present preliminary study, we investigate the case of the SagDEG (the best known satellite galaxy in the Milky Way crossing the solar neighbourhood) analyzing the consequences of its dark matter stream contribution to the galactic halo on the basis of the DAMA/NaI annual modulation data. The present analysis is restricted to some WIMP candidates and to some of the astrophysical, nuclear and particle Physics scenarios. Other candidates such as e.g. the light bosonic ones, we discussed elsewhere, and other non thermalized substructures are not yet addressed here.