Diffuse Gamma Flux from Antiproton Annihilation in our Galaxy

The all-sky survey in high-energy gamma rays (E > 30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma-Ray Observatory provides a unique opportunity to examine in detail the diffuse gamma-ray emission. The observed diffuse emission has a Galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation as well an almost uniformly distributed component that is generally believed to originate outside the Galaxy. The results of the observations have been interpreted as the extragalactic high-energy gamma-ray emission arising primarily from unresolved gamma-ray-emitting blazars. We considered another possible origin of the diffuse gamma-ray flux, namely, as originating from the annihilation of the antiprotons with the interstellar medium.