EGRET PULSAR UPPER LIMITS

The 3.5 year database of the Energetic Gamma Ray Experiment Telescope (EGRET) has been surveyed for gamma-ray emission from all known spin-p owered pulsars. Using contemporaneous timing solutions, upper limits o n pulsed emission were obtained for 350 pulsars. Limits to unpulsed ga mma radiation were obtained for all cataloged pulsars. No new detectio ns were found, although there is evidence for localized excesses at th e positions of a few of these pulsars. No correlation was however foun d between E over dot/d(2) and the sources of such unpulsed excesses. A number of models predict the gamma-ray luminosity from pulsars as a f unction of measurable pulsar parameters. The functional form of models are tested for the six detected pulsars above 100 MeV and we find tha t the luminosity does not scale with the pulsar parameters as predicte d. Furthermore, some flux upper limits contradict the model prediction s, which seems to indicate that the current models of gamma-ray pulsar s are still incomplete.