The highest-energy photons seen by the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory

During its 9 year lifetime, the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) detected 1506 cosmic photons with measured energy E > 10 GeV. Of this number, 187 are found within a 1 degrees of sources that are listed in the Third EGRET Catalog and were included in determining the detection likelihood, flux, and spectra of those sources. In particular, five detected EGRET pulsars are found to have events above 10 GeV, and together they account for 37 events. A pulsar not included in the Third EGRET Catalog has two events, both with the same phase and in one peak of the lower energy gamma-ray light curve. Most of the remaining 1319 events appear to be diffuse Galactic and extragalactic radiation based on the similarity of their spatial and energy distributions with the diffuse model and in the E > 100 MeV emission. No significant time clustering that would suggest a burst was detected.