Constraints from thermal Sunyaev-Zeldovich cluster counts and power spectrum combined with CMB

Abstract

Thermal Sunyaev-Zel'dovich effect is one of the recent probes of cosmology and large scale structures. We update constraints on cosmological parameters from galaxy clusters observed by the Planck satellite in a first attempt to combine cluster number counts and power spectrum of hot gas, using the new value of the optical depth, and sampling at the same time on cosmological and scaling-relation parameters. We find that in the $\Lambda$CDM model, the addition of tSZ power spectrum provides only small improvements with respect to number counts only, leading to the $68\%$ c.l. constraints $\Omega_m = 0.32 \pm 0.02$, $\sigma_8 = 0.77\pm0.03 $ and $\sigma_8 (\Omega_m/0.3)^{1/3}= 0.78\pm0.03$ and lowering the discrepancy with CMB primary anisotropies results (updated with the new value of $\tau$) to $\simeq 1.6\, \sigma$ on $\sigma_8$. We analyse extensions to standard model, considering the effect of massive neutrinos and varying the equation of state parameter for dark energy. In the first case, we find that the addition of tSZ power spectrum helps in strongly improving cosmological constraints with respect to number counts only results, leading to the $95\%$ upper limit $\sum m_{\nu}< 1.53 \, \text{eV}$. For the varying dark energy EoS scenario, we find again no important improvements when adding tSZ power spectrum, but still the combination of tSZ probes is able in providing constraints, producing $w = -1.0\pm 0.2$. In all cosmological scenari the mass bias to reconcile CMB and tSZ probes remains low: $(1-b)\lesssim 0.66$ as compared to estimates from weak lensing and Xray mass estimate comparisons or numerical simulations.