Timing Characteristics of the Hard X-ray Emission from Bright X-ray Pulsars Based on INTEGRAL Data

TL;DR

This paper analyzes timing data from ten bright X-ray pulsars observed by INTEGRAL, examining pulse profiles, their energy and luminosity dependence, and changes near cyclotron frequencies to better understand pulsar emission mechanisms.

Contribution

It provides the first detailed study of how pulsed fraction varies with luminosity and energy in bright X-ray pulsars, based on INTEGRAL observations.

Findings

Pulse profiles depend on energy and luminosity.

Pulsed fraction varies with luminosity and energy.

Changes near cyclotron frequencies were investigated.

Abstract

We review the results of a timing analysis of the observations for ten bright X-ray pulsars (with fluxes >100 mCrab in the 20-100 keV energy band) that fell within the INTEGRAL field of view from 2003 to 2007. The dependence of the pulse profile on the energy and intrinsic source luminosity has been investigated; particular attention has been paid to searching for changes in the pulse profile near the cyclotron frequency. The dependence of the pulsed fraction for X-ray pulsars on their luminosity and energy band has been studied in detail for the first time.