Left: phase evolution of the absorption column density. The light grey stripes indicate ingress and egress transitions, while the dark grey stripe indicates the eclipse. The full black line corresponds to a Castor et al. (1975) wind model fit using system parameters from Coley et al. (2015). A clear excess over the model can be seen for phases previous to the eclipse, suggesting an additional contributing component than just wind absorption. Right: Fe Kα unabsorbed EW against the absorption column. The labels are phase ordered. The linear behaviour in non-eclipsing phases suggests that the Fe line emission region closely follows the NS orbital motion.