Radiation pressure at the upper neutron star atmosphere in super-critical X-ray pulsars

Abstract

This paper shows the distribution of X-ray flux on neutron stars in super-critical X-ray pulsars to display the effects of varying accretion column heights on the material redistribution and atmospheric structure. This study calculates the flux distribution for different column heights and geometric configurations using a point source approximation for a neutron star being influenced by an accretion column. Our findings show that the distribution of X-ray flux depends on the column’s height. In other words, larger columns lead to relatively lower homogenous distributions throughout the surface, whereas lower columns produce more complicated and diverse flux patterns. These variations point to considerable localized differences in temperature and density of the atmosphere, which may affect the X-ray spectra that the neuron star emits. Our follow trends set by earlier research on X-ray pulsars and show promising boundary applications to other high-energy astrophysical systems, including black hole binaries and active galactic nuclei, and are consistent with prior investigations of X-ray pulsars. Studies being done in the future should use more realistic geometries, magnetic field effects, and relativistic corrections. This is because the point source approximation does offer valuable insights, but does not fully depict the complexity of a real accretion column. Investigating the effects of variations in accretion rates on atmospheric dynamics and flux distribution is beneficial to improving upon this study. Contributing to our understanding of high-energy astrophysical environments, this work offers the foundation for developing models for X-ray flux distribution in accretion neutron stars.