The Remarkable Similarity of Massive Galaxy Clusters from z ∼ 0 to z ∼ 1.9
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305 (United States)
- Fermi National Accelerator Laboratory, Batavia, IL 60510-0500 (United States)
- Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)
- Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States)
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
- Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7 (Canada)
- Huntingdon Institute for X-ray Astronomy, LLC (United States)
We present the results of a Chandra X-ray survey of the eight most massive galaxy clusters at z > 1.2 in the South Pole Telescope 2500 deg{sup 2} survey. We combine this sample with previously published Chandra observations of 49 massive X-ray-selected clusters at 0 < z < 0.1 and 90 Sunyaev–Zel’dovich–selected clusters at 0.25 < z < 1.2 to constrain the evolution of the intracluster medium (ICM) over the past ∼10 Gyr. We find that the bulk of the ICM has evolved self-similarly over the full redshift range probed here, with the ICM density at r>0.2R{sub 500} scaling like E(z){sup 2}. In the centers of clusters (r≲0.01R{sub 500}), we find significant deviations from self-similarity (n{sub e}∝E(z){sup 0.2±0.5}), consistent with no redshift dependence. When we isolate clusters with overdense cores (i.e., cool cores), we find that the average overdensity profile has not evolved with redshift—that is, cool cores have not changed in size, density, or total mass over the past ∼9–10 Gyr. We show that the evolving “cuspiness” of clusters in the X-ray, reported by several previous studies, can be understood in the context of a cool core with fixed properties embedded in a self-similarly evolving cluster. We find no measurable evolution in the X-ray morphology of massive clusters, seemingly in tension with the rapidly rising (with redshift) rate of major mergers predicted by cosmological simulations. We show that these two results can be brought into agreement if we assume that the relaxation time after a merger is proportional to the crossing time, since the latter is proportional to H(z){sup −1}.
- OSTI ID:
- 22876078
- Journal Information:
- Astrophysical Journal, Vol. 843, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
X-ray cavities in a sample of 83 SPT-selected clusters of galaxies: Tracing the evolution of AGN feedback in clusters of galaxies out to z = 1.2
Xray cavities in a sample of 83 SPT-selected clusters galaxies. Tracing the evolution of AGN feedback in clusters of galaxies out to z=1.2