Top panel: EPIC-pn spectral residuals for our baseline model xillver + tbnew_pcf*(blackbody + power law) fitted in the 0.3–10 keV band, for OBS1 (black) and OBS2 (red). Top left panel, Model A: spectral residuals after the addition of a cold partially covering absorber, xillver + tbnew_pcf*(blackbody + power law). Middle left panel, Model B: spectral residuals for a double partial covering absorber model, xillver + tbnew_pcf1*tbnew_pcf2*powerlaw. Bottom left panel, Model C: spectral residuals for a double Comptonisation model, xillver + tbnew_pcf*(optxagnf). Data were visually rebinned to a significance of 15σ (Xspec command setplot rebin). Top right panel: theoretical model A; middle right panel: theoretical model B; bottom right panel: theoretical model C. Black lines always refer to OBS1, and red lines to OBS2.