  Several independent observations of the Galactic core suggest hitherto
unexplained sources of energy. We suggest that dark matter in the form of dense
antimatter nuggets could provide a natural site for electron and proton
annihilation, providing 511 keV photons, gamma-rays, and diffuse keV x-ray
radiation. We show that identifying dark matter as antimatter nuggets is
consistent with the observed emissions, and we make definite predictions about
their spectrum and morphology. If correct, our proposal not only identifies
dark matter and explains baryogenesis, but allows x-ray observations to
directly probe the matter distribution in our Galaxy.
