In the concordance cosmological model, cold dark matter (DM) halos have substructure with masses all the way down to a minimum mass ranging between 10$^{-3}$ to 10$^{-12}$ solar masses. These DM subhalos are expected to be highly concentrated compared to field halos, and some of them might be very close to us. If DM is made of WIMPs that self-annihilates into standard particles, some of these halos might be amongst the best astrophysical candidates for gamma-ray indirect DM searches.

Using Via Lactea II and Aquarius simulation results, we estimate the number of subhalos that are better candidates for detection than the Draco dwarf galaxy. As the simulations don't resolve the full DM structure hierarchy, we include the low mass subhalos by extrapolating the subhalo properties found above the mass resolution in the simulations and also taking into account theoretical considerations. We apply bootstrapping techniques to quantify the statistical uncertainties. Our results indicate that there might be up to thousands of low mass subhalos brighter than Draco in gamma-rays. We also perform some subhalo detectability predictions for the Fermi satellite.