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

TL;DR

This paper presents the first all-sky map of the thermal Sunyaev-Zeldovich effect from Planck data, analyzes its power spectrum and higher-order statistics, and derives cosmological constraints on matter fluctuations.

Contribution

It introduces a novel all-sky tSZ map, measures its power spectrum at previously unexplored scales, and uses it to constrain cosmological parameters.

Findings

Measured tSZ power spectrum consistent with Planck SZ catalog

Detected signals from unresolved clusters and warm baryons

Provided constraints on σ8 and Ωm from tSZ data

Abstract

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. These maps show 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 ($\ell < 60$), the major foreground contaminant is the diffuse thermal dust emission. At small angular scales ($\ell > 500$) the clustered Cosmic Infrared Background (CIB) and residual point sources are the major contaminants. These foregrounds are carefully modelled and subtracted. We measure the tSZ power spectrum in angular scales, $0.17^{\circ} \lesssim \theta \lesssim 3.0^{\circ}$, that were previously unexplored. The measured tSZ power spectrum is consistent with that expected from the Planck catalogue of SZ sources, with additional clear evidence of signal from unresolved clusters and, potentially, diffuse warm baryons. We use the tSZ power spectrum to obtain the following cosmological constraints: $\sigma_8(\Omega_{\mathrm{m}}/0.28)^{3.2/8.1}=0.784 \pm 0.016 (68% C.L.). Marginalized band-powers of the Planck tSZ power spectrum and the best-fit model are given. 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 $\sigma_{8}$.