'Half-bare' positron in the inner gap of a pulsar and shift of inter pulse position

TL;DR

This paper explains the frequency-dependent shift of the inter pulse in the Crab pulsar's radiation by proposing that relativistic positrons reflect radiation from the star surface, influenced by the magnetic field inclination.

Contribution

It introduces a novel model where half-bare positrons reflect radiation, accounting for the observed inter pulse shifts across different frequencies.

Findings

Positron reflection explains inter pulse position shifts.

Spectral-angular properties differ from electron curvature radiation.

Magnetic field inclination influences the radiation processes.

Abstract

The pulsed radiation from the Crab pulsar consists of the main pulse (MP) and inter pulse (IP), as well as of the extra pulse components appearing at certain frequencies. It has been studied at many frequencies and contains unique information, which is not available for the majority of the pulsars. One of the mysteries of these data, found by Moffett and Hankins twenty years ago, is the shift of the IP at high radio frequencies compared to lower ones and return to its previous position in the more high-frequency optical and X-ray range. We propose the explanation of these mysterious changes with the frequency through reflection of radiation by relativistic positrons from the star surface. The magnetic field of the pulsar in the pole must be inclined to the surface of the star and affects on the discussed processes. The positrons, which are accelerated towards the surface of the star by the inner gap electric field, radiate as half-bare particles. The spectral-angular properties of this radiation differ from those ones of the electron curvature radiation inside the gap.