Speaker
Description
The Milky Way's Galactic Center may harbor the signal of annihilating
dark matter in a gamma-ray excess, though dwarf galaxies remain dark
in their expected commensurate emission. We incorporate Milky Way dark
matter halo profile uncertainties, as well as an accounting of diffuse
gamma ray emission uncertainties in dark matter annihilation models
for the Galactic Center Extended gamma-ray excess (GCE) detected by
the Fermi Gamma Ray Space Telescope. The range of particle
annihilation rate and masses expand when including these
unknowns. However, two of the most precise empirical determinations of
the Milky Way halo's local density and density profile leave the
signal region to be in considerable tension with dark matter
annihilation searches from combined dwarf galaxy analyses for
single-channel dark matter annihilation models. Accordingly, we
quantify this tension in a joint likelihood analysis. We also show
that astrophysical models and a representative self-interacting dark
matter model avoid the tensions between the GCE signal and lack of a
signal from the dwarfs. Since these arguments disfavor the
intepretation of the GCE as prompt annihilation of dark matter, we set
limits on the cross section for that process.
