Combined analysis of galaxy cluster number count, thermal Sunyaev-Zel'dovich power spectrum, and bispectrum

Understand

The Sunyaev-Zel'dovich (SZ) effect is a powerful probe of the evolution of structures in the universe, and is thus highly sensitive to cosmological parameters $\sigma_8$ and $\Omega_m$, though its power is hampered by the current uncertainties on the cluster mass calibration.

• In this analysis we revisit constraints on these cosmological parameters as well as the hydrostatic mass bias, by performing (i) a robust estimation of the tSZ power-spectrum, (ii) a complete modeling and analysis of the tSZ bispectrum, and (iii) a combined analysis of galaxy clusters number count, tSZ power spectrum, and tSZ bispectrum.
• From this analysis, we derive as final constraints $\sigma_8 = 0.79 \pm 0.02$, $\Omega_{\rm m} = 0.29 \pm 0.02$, and $(1-b) = 0.71 \pm 0.07$.
• These results favour a high value for the hydrostatic mass bias compared to numerical simulations and weak-lensing based estimations.