2025A&A...704A.302M

In a self-similar paradigm of structure formation, the thermal pressure of the hot intra-cluster gas follows a universal distribution, once the profile of each cluster is normalised based on the proper mass and redshift dependencies. The reconstruction of such a universal pressure profile requires an individual estimate of the mass of each cluster. In this context, we present a method to jointly fit, for the first time, the universal pressure profile and individual cluster M₅₀₀ masses over a sample of galaxy clusters, properly accounting for correlations between the profile shape and amplitude, and masses that scale the individual profiles. We demonstrate the power of the method and show that a consistent exploitation of the universal pressure profile and cluster mass estimates when modelling the thermal pressure in clusters is necessary to avoid biases. In particular, the method, informed by a cluster mass scale, outputs individual cluster masses with the same accuracy and greater precision than input masses. Using data from the Cluster HEritage project with XMM-Newton: Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE), we investigate a sample of ∼25 galaxy clusters spanning mass and redshift ranges of 2 ≲ M₅₀₀/10¹⁴ M_⊙ ≲ 14 and 0.07 < z < 0.6.