On the mystery of the interpulse shift in the Crab pulsar

TL;DR

This paper proposes a new curvature radiation mechanism involving returning positrons in the pulsar's polar gap, which may explain the high-frequency interpulse shift observed in the Crab pulsar.

Contribution

It introduces a novel radiation emission process involving returning positrons and surface reflection, providing a potential explanation for the interpulse shift phenomenon.

Findings

The proposed mechanism can account for the interpulse shift at high frequencies.

Interference between curvature and transition radiation explains observed pulsar features.

The model aligns with observations of the Crab pulsar's emission behavior.

Abstract

A new mechanism of radiation emission in the polar gap of a pulsar is proposed. It is the curvature radiation which is emitted by returning positrons moving toward the surface of the neutron star along field lines of the inclined magnetic field and reflects from the surface. Such radiation interferes with transition radiation emitted from the neutron star when positrons hit the surface. It is shown that the proposed mechanism may be applicable for explanation of the mystery of the interpulse shift in the Crab pulsar at high frequencies discovered by Moffett and Hankins twenty years ago.