GAMMA-RAY PULSARS - EMISSION ZONES AND VIEWING GEOMETRIES

There are now a half-dozen young pulsars detected in high-energy photo ns by the Compton Gamma-Ray Observatory, showing a variety of emission efficiencies and pulse profiles. We present here a calculation of the pattern of high-energy emission on the sky in a model which posits ga mma-ray production by charge-depleted gaps in the outer magnetosphere. This model accounts for the radio to gamma-ray pulse offsets of the k nown pulsars, as well as the shape of the high-energy pulse profiles. We also show that about one-third of emitting young radio pulsars will not be detected due to beaming effects, while approximately 2.5 times the number of radio-selected gamma-ray pulsars will be viewed only hi gh energies. Finally we compute the polarization angle variation and f ind that the previously misunderstood optical polarization sweep of th e Crab pulsar arises naturally in this picture. These results strongly support an outer magnetosphere location for the gamma-ray emission.