The Dark Matter Annihilation Signal from Dwarf Galaxies and Subhalos
  Dark Matter annihilation holds great potential for directly probing the
clumpiness of the Galactic halo that is one of the key predictions of the Cold
Dark Matter paradigm of hierarchical structure formation. Here we review the
gamma-ray signal arising from dark matter annihilation in the centers of
Galactic subhalos. We consider both known Galactic dwarf satellite galaxies and
dark clumps without a stellar component as potential sources. Utilizing the Via
Lactea II numerical simulation, we estimate fluxes for 18 Galactic dwarf
spheroidals with published central densities. The most promising source is
Segue 1, followed by Ursa Major II, Ursa Minor, Draco, and Carina. We show that
if any of the known Galactic satellites can be detected, then at least ten
times more subhalos should be visible, with a significant fraction of them
being dark clumps.
