Inner magnetospheric accelerators in high magnetic field pulsars

Abstract

Photon splitting is a QED process that can potentially suppress pair production in the inner magnetosphere of a pulsar with a super-strong magnetic field, and hence, may quench radio emission from these objects. While it is unknown how many splitting modes really operate in super-critical fields, we derive gap parameters of a high magnetic field pulsar for both the vacuum-type gap and the space-charge-limited flow accelerator under the assumption that all three splitting modes permitted by QED operate. The competition between photon splitting and pair production depends on the gap parameters, and the ``photon-splitting-dominant'' line for both cases are derived. We discuss the implications of these results and the possible connection of the high magnetic field pulsars with the anomalous X-ray pulsars and soft gamma-ray repeaters which are conjectured to be magnetars.