CHEX-MATE. Relationship between X-ray and millimetre inferences of galaxy cluster temperature profiles

Thermodynamic profiles from X-ray and millimetre observations of galaxy clusters are often compared under the simplifying assumptions of a smooth, spherically symmetric intracluster medium. These approximations lead to expected discrepancies in the inferred profiles, which can provide insights into the cluster structure or cosmology. Motivated by this, we present a joint XMM-Newton and Planck analysis of 116 CHEXMATE clusters to measure η T = T X /T SZ, X , the ratio between spectroscopic X-ray temperatures and a temperature proxy derived from SunyaevZel’dovich (SZ) pressures and X-ray densities. We considered relativistic corrections to the thermal SZ signal and implemented X-ray absorption by Galactic molecular hydrogen. The η T distribution has a mean of 1.01 ± 0.03, with average changes of 8.1% and 2.7% when relativistic corrections and molecular hydrogen absorption are not included, respectively. The η T distribution is positively skewed, with the scatter mostly affected by cluster morphology: relaxed clusters are closer to unity and less scattered than mixed and disturbed systems. We find little or no correlation with redshift, mass, or temperature.