Observed cross-correlation between the tSZ map (y_c) of known clusters and the Planck frequency maps (T_ν), from 100 to 857 GHz. The data are presented as black circles, the tSZ auto-correlation is in green and the total model y_c–T_ν accounting for tSZ-CIB correlation is in red for the best-fit of the CIB and tSZ spectra. All power spectra are presented in Compton-parameter units. Uncertainties are dominated by foreground residuals; thus they are highly correlated from one channel to another.