Disrupted Globular Clusters Can Explain the Galactic Center Gamma Ray
  Excess
  The Fermi satellite has recently detected gamma ray emission from the central
regions of our Galaxy. This may be evidence for dark matter particles, a major
component of the standard cosmological model, annihilating to produce
high-energy photons. We show that the observed signal may instead be generated
by millisecond pulsars that formed in dense star clusters in the Galactic halo.
Most of these clusters were ultimately disrupted by evaporation and
gravitational tides, contributing to a spherical bulge of stars and stellar
remnants. The gamma ray amplitude, angular distribution, and spectral
signatures of this source may be predicted without free parameters, and are in
remarkable agreement with the observations. These gamma rays are from fossil
remains of dispersed clusters, telling the history of the Galactic bulge.
