Investigating cluster astrophysics and cosmology with cross-correlation of the thermal Sunyaev–Zel'dovich effect and weak lensing

Abstract

Recent detections of the cross-correlation of the thermal Sunyaev-Zel'dovich\n(tSZ) effect and weak gravitational lensing (WL) enable unique studies of\ncluster astrophysics and cosmology. In this work, we present constraints on the\namplitude of the non-thermal pressure fraction in galaxy clusters, $\\alpha_0$,\nand the amplitude of the matter power spectrum, $\\sigma_8$, using measurements\nof the tSZ power spectrum from Planck, and the tSZ-WL cross-correlation from\nPlanck and the Red Cluster Sequence Lensing Survey. We fit the data to a\nsemi-analytic model with the covariance matrix using $N$-body simulations. We\nfind that the tSZ power spectrum alone prefers $\\sigma_8 \\sim 0.85$ and a large\nfraction of non-thermal pressure ($\\alpha_0 \\sim 0.2$-$0.3$). The tSZ-WL\ncross-correlation on the other hand prefers a significantly lower $\\sigma_8\n\\sim 0.6$, and low $\\alpha_0 \\sim 0.05$. We show that this tension can be\nmitigated by allowing for a steep slope in the stellar-mass-halo-mass relation,\nwhich would cause a reduction of the gas in low-mass halos. In such a model,\nthe combined data prefer $\\sigma_8 \\sim 0.7$ and $\\alpha_0 \\sim 0.2$,\nconsistent with predictions from hydrodynamical simulations.\n