Gamma-ray emission from rotation-powered pulsars

Abstract

Using a simplified model of cascade pair creation over pulsar polar caps presented in two previous papers, we investigate the expected gamma-ray output from pulsars' low altitude particle acceleration and pair creation regions. We divide pulsars into several categories, based on which mechanism truncates the particle acceleration off the polar cap, and give estimates for the expected luminosity of each category. We find that inverse Compton scattering above the pulsar polar cap provides the primary gamma rays which initiate the pair cascades in most pulsars. This reduces the expected $\gamma$-ray luminosity below previous estimates which assumed curvature gamma ray emission was the dominant initiator of pair creation in all pulsars.