Prospects for Detecting Gamma Rays from Annihilating Dark Matter in
  Dwarf Galaxies in the Era of DES and LSST
  Among the most stringent constraints on the dark matter annihilation cross
section are those derived from observations of dwarf galaxies by the Fermi
Gamma-Ray Space Telescope. As current (e.g., Dark Energy Survey, DES) and
future (Large Synoptic Survey Telescope, LSST) optical imaging surveys discover
more of the Milky Way's ultra-faint satellite galaxies, they may increase
Fermi's sensitivity to dark matter annihilations. In this study, we use a
semi-analytic model of the Milky Way's satellite population to predict the
characteristics of the dwarfs likely to be discovered by DES and LSST, and
project how these discoveries will impact Fermi's sensitivity to dark matter.
While we find that modest improvements are likely, the dwarf galaxies
discovered by DES and LSST are unlikely to increase Fermi's sensitivity by more
than a factor of ~2-4. However, this outlook may be conservative, given that
our model underpredicts the number of ultra-faint galaxies with large potential
annihilation signals actually discovered in the Sloan Digital Sky Survey. Our
simulation-based approach focusing on the Milky Way satellite population
demographics complements existing empirically-based estimates.
