Sensitivity of XMM-Newton observations to typical Planck SZ sources. The expected signal-to-noise ratio (S/N) of the cluster detection in the  [0.3–2] keV energy band with the epic camera is plotted as a function of redshift for an exposure time of 10 ks assuming two typical SZ fluxes. See text for details of the model assumed to convert SZ to X-ray flux and count rate. The dash-dotted line indicates the S/N required for 10% uncertainty on the temperature measurement of an 8 keV cluster.