GAMMA-RAY PULSARS AND MASSIVE STARS IN THE SOLAR NEIGHBORHOOD

We revisit the association of unidentified Galactic plane EGRET source s with tracers of recent massive star formation and death. Up-to-date catalogs of OB associations, supernova remnants (SNRs), young pulsars, H II regions, and young open clusters were used in finding counterpar ts for a recent list of EGRET sources. It has been argued for some tim e that EGRET source positions are correlated with SNRs and OB associat ions as a class; we extend such analyses by finding additional counter parts and assessing the probability of individual source identificatio ns. Among the several scenarios relating EGRET sources to massive star s, we focus on young neutron stars as the origin of the gamma-ray emis sion. The characteristics of the candidate identifications are compare d to the known gamma-ray pulsar sample and to detailed Galactic popula tion syntheses using our outer gap pulsar model of gamma-ray emission. Both the spatial distribution and luminosity function of the candidat es are in good agreement with the model predictions; we infer that you ng pulsars can account for essentially all of the excess low latitude EGRET sources. We show that with this identification, the gamma-ray po int sources provide an important new window into the history of recent massive star death in the solar neighborhood.