The X-Ray Properties of GX 301-2 (4U 1223-62)

Abstract

The X-ray luminosity of the X-ray binary pulsar GX 301 - 2 exhibits a strong maximum near periastron passage of the neutron star, or phase 0, but with the peak 0.05 in phase before. During the interval between phase 0.9 and 0.25, during periods when the absorption was high, the X-ray spectra indicate a strong low-energy excess that may be modeled by X-ray emission which is scattered around a region of enhanced wind density by the less dense ambient wind. A model of enhanced mass loss from the primary toward the neutron star generating the dense gas stream is noted to be able to reproduce the orbital phase-dependence of the X-ray luminosity and absorption.