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We propose that some of the high-latitude unidentified EGRET gamma-raysources could be the result of gravitational lensing amplification of theinnermost regions of distant, faint, active galactic nuclei. These objects havegamma-ray emitting regions small enough as to be affected by microlensing ofstars in interposed galaxies. We compute the gravitational amplification takinginto account effects of the host galaxy of the lens and prove that, whereas theinnermost gamma-ray regions can be magnified up to thousand times, there is noamplification at radio frequencies, leading to the observed absence of strongcounterparts. Some new effects in the spectral evolution of a gravitationalmicrolensed gamma-ray AGN are predicted. Within a reasonable range of lensingparameters, and/or types of sources, both variable and non-variable EGRETdetections at high latitudes can be explained by microlensing. The samephenomenon could also have an important incidence among the future GLASTdetections at high-latitudes.Comment: Accepted for publication in The Astrophysical Journal. Scheduled to  appear in April, 2002. 2 figure

Gravitational Lensing as a Possible Explanation for Some Unidentified Gamma‐Ray Sources at High Latitudes