Observing the Universe at millimetre wavelengths

Probing the Hubble constant from X-ray and millimetre observations of CHEX-MATE galaxy clusters

27 juin 2023, 14:55

20m

Amphitheatre (LPSC Grenoble)

Tuesday P2

Orateur

Federico De Luca (Università degli Studi di Roma Tor Vergata)

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, ${\eta }_T=k{T}_{XMM}/(P_{Planck}/n{e}_{XMM}$), 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 $H_0={67.3}_{-2.1}^{+2.2}\mathrm{k}\mathrm{m}{\mathrm{s}}^{-1}\mathrm{M}\mathrm{p}{\mathrm{c}}^{-1}$.

Documents de présentation

deluca_mmuniverse.pdf