Fit and residuals of the X-ray spectrum of PSZ2G263.68-22.55 when we assume the molecular hydrogen column density from Bourdin et al. (in prep.) (left panel) or when N_H is free to vary in the fit (right). For the three cameras (EPN, MOS1, and MOS2) of the XMM-Newton telescope, the light blue curve is the fitted model of the cluster spectrum, the dark blue line represents the total contribution from the background or foreground components (CXB plus QPB, SP, and the Galactic emission, see Sect. 3.2.2), the red curve is the sum of these two components, and the black curve is the observed spectrum.