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

Year: 2026

Type: article

Abstract: 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 CHEX-MATE clusters to measure ηT = TX/TSZ, X, the ratio between spectroscopic X-ray temperatures and a temperature proxy derived from Sunyaev-Zel’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 ηT 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 ηT 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.

Source: Springer Link (Chiba Institute of Technology)

DOI: 10.1051/0004-6361/202557787/pdf

Institutions: University of Rome Tor Vergata, Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata, Agenzia Spaziale Italiana, Argonne National Laboratory, Sapienza University of Rome, University of Geneva, Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Osservatorio di Astrofisica e Scienza dello Spazio, National Institute for Astrophysics, University of Naples Federico II, Center for Astrophysics Harvard & Smithsonian, University of Modena and Reggio Emilia, Istituto di Radioastronomia di Bologna, University of Bologna, University of Manchester, Korea Advanced Institute of Science and Technology, Centre National de la Recherche Scientifique, Institut National de Physique Nucléaire et de Physique des Particules, Université Grenoble Alpes, University of Bristol, Université Toulouse III - Paul Sabatier, Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, Istituto Nazionale di Fisica Nucleare, Sezione di Genova, Université Paris Cité, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Astrophysique, Instrumentation et Modélisation, California Institute of Technology

Language: English

Topic: Galaxies: Formation, Evolution, Phenomena

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, University of Chicago, European Commission, National Research Foundation, Agence Nationale de la Recherche, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Nuclear Safety and Security Commission, National Research Foundation of Korea, Korea Advanced Institute of Science and Technology, Office of Science, HORIZON EUROPE Framework Programme, Science and Technology Facilities Council, Astrophysics Division, Argonne National Laboratory, HORIZON EUROPE European Research Council

OpenAlex ID: W7124806388