Centroid energy of FeKα with a Gaussian fit overplotted (blue profile). The mean value is 6.42 ± 0.02 keV, compatible with Fe i-xviii. Even though we have 60 detections of FeKα, in this plot we only see 55. Five cases fulfil the requirements of detection, but the low signal-to-noise rations do not permit finding an accurate centroid energy. They have not been included in this plot. In these five cases we set the centroid energy of FeKα to ~6.4 keV.