Past studies have identified a spatially extended
excess of ~1-3 GeV gamma rays from the region
surrounding the Galactic Center, consistent with the
emission expected from annihilating dark matter. Recent
improvements in the analysis techniques have found
this excess to be robust and highly statistically
significant, with a spectrum, angular distribution, and
overall normalization that is in good agreement with that
predicted by simple annihilating dark matter models. For
example, the signal is very well fit by a 31-40 GeV dark
matter particle annihilating to b quarks with an
annihilation cross section of sigma v = (1.7-2.3) x 10^-26
cm^3/s. Furthermore, the angular distribution of the
excess is approximately spherically symmetric and
centered around the dynamical center of the Milky Way
(within ~0.05 degrees of Sgr A*), showing no sign of
elongation along or perpendicular to the Galactic Plane.
The signal is observed to extend to at least 10 degrees
from the Galactic Center, disfavoring the possibility that
this emission originates from millisecond pulsars.