Title: Exess of EGRET Galactic Diffuse Gamma Rays: a Signal of Dark Matter Annihilation?


The excess of diffuse galactic gamma rays in the range between 1 and 100 GeV, as observed by the EGRET satellite, shows all the key features from WIMP annihilation: 1) the energy spectrum of the excess is the same in all sky directions and is consistent with the pi0 decays from monoenergetic quarks originating from WIMP annihilation for a WIMP mass between 50-100 GeV 2) the intensity distribution of the excess in the sky is used to determine the halo profile, which, outside the plane of the galaxy, was found to correspond to an isothermal (cored) profile and excludes the cuspy NFW profile 3) in the plane of the galaxy the excess shows strong substructure: two rings at radii of 4 and 14 kpc, which are correlated with the ring of molecular hydrogen at 4 kpc and the ring of stars at 14 kpc, thought to orginate from the infall of a satellite galaxy 4) these rings yield a change of slope at R=1.1R0 in the rotation curve in agreement with data and are consistent with the high local surface density observed recently 5) all features and cross sections are consistent with the WIMP being the neutralino from Minimal Supersymmetry