Effect of geodetic precession on the evolution of pulsar high-energy pulse profiles as derived with the striped-wind model

TL;DR

This paper models how geodetic precession affects high-energy pulse profiles in pulsars using the striped-wind model, predicting observable changes in X-ray and gamma-ray emissions for certain binary configurations.

Contribution

It introduces a detailed computation of pulse profile variations due to geodetic precession within the striped-wind model, comparing it with other emission patterns and predicting potential future detections.

Findings

Significant pulse profile changes occur with sufficient misalignment.

Distinct features differentiate the striped-wind model from other models.

Predictions for future high-energy emission detections in relativistic binaries.

Abstract

Geodetic precession has been observed directly in the double-pulsar system PSR J0737-3039. Its rate has even been measured and agrees with predictions of general relativity. Very recently, the double pulsar has been detected in X-rays and gamma-rays. This fuels the hope observing geodetic precession in the high-energy pulse profile of this system. Unfortunately, the geometric configuration of the binary renders any detection of such an effect unlikely. Nevertheless, this precession is probably present in other relativistic binaries or double neutron star systems containing at least one X-ray or gamma-ray pulsar.}{We compute the variation of the high-energy pulse profile expected from this geodetic motion according to the striped-wind model. We compare our results with two-pole caustic and outer gap emission patterns.}{For a sufficient misalignment between the orbital angular momentum and the spin angular momentum, a significant change in the pulse profile as a result of geodetic precession is expected in the X-ray and gamma-ray energy band.}{The essential features of the striped wind are indicated in several plots showing the evolution of the maximum of the pulsed intensity, the separation of both peaks, if present, and the variation in the width of each peak. We highlight the main differences with other competing high-energy models.}{We make some predictions about possible future detection of high-energy emission from double neutron star systems with the highest spin precession rate. Such observations will definitely favour some pulsed high-energy emission scenarios.