ASSOCIATION OF UNIDENTIFIED, LOW-LATITUDE EGRET SOURCES WITH SUPERNOVA-REMNANTS

We propose that some of the unidentified Galactic plane (-10 degrees < b < 10 degrees) sources listed in the first EGRET catalog (Fichtel et al. 1994) are associated with nearby supernova remnants. The probabil ity that the association of strong EGRET sources with supernova remnan ts is due to chance alignment is found to be less than or similar to 1 /2200. Three of the most convincing associations are radio-bright, nea rby shell remnants and a fourth is associated with a plerion. We exami ne possible gamma-ray production mechanisms and conclude that pion pro duction and decay from high-energy protons interacting with the remnan t gas could produce the gamma rays. The energetics of this process are in accord with theories of cosmic ray production through supernova sh ock acceleration. The identification of pi(0)-decay features in the ga mma-ray spectra of supernova remnants would support this interpretatio n.