Top panel: ratio of the EPIC spectra in the 5–8.5 keV energy range with respect to an absorbed power law. All the instruments (pn in blue, MOS1 in magenta, and MOS2 in green) detected the Fe Kα and found a trough at about 7.5 keV. Bottom panel: blind line scan result between the normalisation and line energy, adopted on the pn-MOS spectra, where a Gaussian is left free to vary in the 5–8.5 keV energy range. The colour bar on the right indicates the significance of the lines for 2 degrees of freedom and the solid black contours correspond to 68%, 90%, and 99%.