Observed spectra of Fe XXVI 1.778 Å, Fe XXV 1.859 Å, Ca XX 3.018 Å, Ar XVIII 3.731 Å, S XVI 4.734 Å and Si XIV 6.184 Å are shown in vertical columns from left to right. Each column presents spectra at ten orbital phases from 0.05 (top) to 0.95 (bottom). The x-axis represents the velocity shift from the line wavelength (in units of 1000 km/s), while the y-axis shows the observed flux (photons/s/keV/cm² on Earth) with error bars and the model-fit (solid line)