Soft Gamma-ray Emissions from the Polar Cap Cascade Region

Zhu, Yiyuan

Polar cap cascade is one of the fundamental physical process of the pulsar. However the emission from cascade region has not been confirmed in the high energy observations: GeV emission from the pulsars mainly comes from outer magnetosphere around the light cylinder. So called MeV pulsars may be the evidence of the emission from the polar cap cascade. To discuss such a possibility, we simulate the pair-creation process in the polar cap cascade region. Comparing the synchrotron emissions from the pairs with the observation on MeV pulsars, we suggest that the soft gamma-ray emissions of the MeV pulsar are coming from the polar cap cascade region.