Beaming of polarized radiation in subcritical X-ray pulsars
Abstract
Radiation of X-ray pulsars is powered by accretion on the neutron star surface from a binary companion under the influence of a strong magnetic field. We study beaming of this radiation in the case of subcritical X-ray pulsars, where it is formed in the accretion channel close to the neutron star surface. We solve equations of the hydrodynamics and radiative transfer of two coupled polarization modes in the accretion channel numerically, taking into account resonant Compton scattering and vacuum polarization. The beaming patterns are obtained for different accretion rates, photon energies and polarizations, and for different models of the neutron star surface radiation. The calculated beaming patterns are converted into light curves for both the intensity and polarization, taking into account the effects of General Relativity. These beaming patterns and light curves are found to be strongly affected by the resonant Compton scattering for photon energies comparable with the electron cyclotron energy. In particular, the angular redistribution of radiation near the cyclotron resonance may reduce the light-curve modulation amplitude, which is consistent with observational indications of a suppressed pulsed fraction at these energies.
Keywords
Cite
@article{arxiv.2604.01218,
title = {Beaming of polarized radiation in subcritical X-ray pulsars},
author = {I. D. Markozov and A. Y. Potekhin and A. D. Kaminker and A. A. Mushtukov},
journal= {arXiv preprint arXiv:2604.01218},
year = {2026}
}
Comments
17 pages, Selected Papers from "The Modern Physics of Compact Stars and Relativistic Gravity 2025" (Yerevan, Sept. 23-26, 2025), submitted to Particles