2025/03/31 by Arnab Sarkar, M. McDonald, Sarkar, Arnab +25
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.2504.00113
openalex publication_date 2025/03/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present joint South Pole Telescope (SPT) and XMM-Newton observations of 8 massive galaxy clusters (0.8--1.7×1015 M\odot) spanning a redshift range of 0.16 to 0.35. Employing a novel SZ+X-ray fitting technique, we effectively constrain the thermodynamic properties of these clusters out to the virial radius. The resulting best-fit electron density, deprojected temperature, and deprojected pressure profiles are in good agreement with previous observations of massive clusters. For the majority of the cluster sample (5 out of 8 clusters), the entropy profiles exhibit a self-similar behavior near the virial radius. We further derive hydrostatic mass, gas mass, and gas fraction profiles for all clusters up to the virial radius. Comparing the enclosed gas fraction profiles with the universal gas fraction profile, we obtain non-thermal pressure fraction profiles for our cluster sample at >R500, demonstrating a steeper increase between R500 and R200 that is consistent with the hydrodynamical simulations. Our analysis yields non-thermal pressure fraction ranges of 8--28% (median: 15 ± 11%) at R500 and 21--35% (median: 27 ± 12%) at R200. Notably, weak-lensing mass measurements are available for only four clusters in our sample, and our recovered total cluster masses, after accounting for non-thermal pressure, are consistent with these measurements.