Title: Evidence for Unresolved Gamma-Ray Point Sources in the Inner Galaxy

Abstract: 

We present a new method to characterize unresolved point sources (PSs),  generalizing traditional template fits to account for non-Poissonian photon statistics.  We apply this method to Fermi Large Area Telescope gamma-ray data to characterize PS populations at high latitudes and in the Inner Galaxy.  We find that PSs (resolved and unresolved) account for ~50% of the total extragalactic gamma-ray background in the energy range ~1.9 to 11.9 GeV.  Within 10 degrees of the Galactic Center with |b| > 2 degrees, we find that ~5--10% of the flux can be accounted for by a population of unresolved PSs, distributed consistently with the observed ~GeV gamma-ray excess in this region. The excess is fully absorbed by such a population, in preference to dark-matter annihilation. The inferred source population is dominated by near-threshold sources, which may be detectable in future searches.