Planck 2013 results. XXI. All-sky Compton parameter power spectrum and high-order statistics

We have constructed the first all-sky map of the thermal Sunyaev-Zeldovich (tSZ) effect by applying specifically tailored component separation algorithms to the 100 to 857 GHz frequency channel maps from the Planck survey. This map shows an obvious galaxy cluster tSZ signal that is well matched with blindly detected clusters in the Planck SZ catalogue. To characterize the signal in the tSZ map we have computed its angular power spectrum. At large angular scales (‘ 500) the clustered cosmic infrared background (CIB) and residual point sources are the major contaminants. These foregrounds are carefully modelled and subtracted. We thus measure the tSZ power spectrum over angular scales 0:17 < < 3:0 that were previously unexplored. The measured tSZ power spectrum is consistent with that expected from the Planck catalogue of SZ sources, with clear evidence of additional signal from unresolved clusters and, potentially, diffuse warm baryons. Marginalized band-powers of the Planck tSZ power spectrum and the best-fit model are given. We use the tSZ power spectrum to obtain the following cosmological constraint: 8( m=0:28) 0:40 = 0:784 0:016(68 % C:L:). This result is in weak tension (at 2.7 ) with the Planck measurements of the primary anisotropies in the cosmic microwave background. The non-Gaussianity of the Compton parameter map is further characterized by computing its 1D probability distribution function and its bispectrum. These are used to place additional independent constraints on 8.