Speaker
Description
Independent constraints on the Hubble constant ($H_0$) from local distance ladders and early Universe CMB data can be derived from cluster sizes by combining X-ray and millimetre observations of the intracluster medium. Using XMM-Newton and Planck data, we present the inference on $H_0$ by studying systematic mismatches, $\eta_T$, between X-ray and millimetre temperature (or pressure) estimates: $T_{X-ray} = \eta_T P_{SZ}/n_{e, X-ray}$. However, cosmology is only one of the factors influencing $\eta_T$. Several astrophysical and observational systematics contribute to this discrepancy, including assumptions regarding the cluster structure, such as spherical symmetry, clumpiness, as well as the chemical composition of the ICM, or the neglect of relativistic effects in the SZ signal. To systematically account for all these effects, we employ a Bayesian approach, comparing observational data with numerical simulations from The Three Hundred project. This framework is applied to the CHEX-MATE sample, consisting of 116 clusters of Planck-selected systems. Additionally, we evaluate the impact of relativistic corrections to the SZ signal on thermodynamic profiles and their effect on the inferred value of $H_0$.
| Would you be interested in presenting a poster if the conference is oversubcribed? | No |
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