Orateur
Description
Assuming spherical symmetry, joint X-ray and millimetre observations of galaxy cluster atmospheres allow us to measure intra-cluster distances. Using XMM-Newton and Planck observations of CHEX-MATE galaxy clusters, we investigate the relationship between X-ray and X-ray+mm inferences of cluster temperature profiles. The average ratio between X-ray and X-ray+mm temperatures, $\eta_T=kT_{XMM}\;\,/(P_{Planck}\;\:/ne_{XMM}\;\,$), is distributed around 1, in agreement with previous estimates of pressure ratios obtained using the same instruments. We find that the overall distribution of $\eta_T$ is affected by the morphological state of galaxy clusters. On the other hand, the $\eta_T$ distribution does not exhibit any significant dependence on cluster masses or redshifts. Combining $\eta_T$ values with Bayesian priors on the cluster morphological states obtained from hydrodynamical simulations of The Three Hundred project, we used CHEX-MATE clusters as cosmological rulers and derived a value of the Hubble constant of $H_0 = 67.3^{+2.2}_{-2.1} \;\,\rm km \,s^{-1}\, Mpc^{-1}$.
