AAS 197, January 2001
Session 94. HEAD II: High Energy Constraints on Extended Structures
Special Session Oral, Wednesday, January 10, 2001, 1:30-3:00pm, Golden Ballroom

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[94.03] Galaxy Clusters as Cosmological Probes

J. J. Mohr (University of Illinois)

Galaxy clusters are powerful tools for studying the evolution of our universe. With Chandra and XMM-Newton observations of high redshift clusters, we can now begin testing models for the evolution of cluster structure. I will review recent progress in studies of galaxy cluster scaling relations. Scaling relations allow us to assess the regularity in the cluster population; interestingly, there is sufficient regularity to allow relative distance measurements to redshifts z~.5. Disagreements between observed and simulated local scaling relations suggest that there must be a heat source for the intracluster medium in addition to the shocks and compressional heating during cluster formation. New studies at higher redshift allow us to test this model and constrain the heating epoch.

The last two years has seen rapid progress in attempts to use Sunyaev-Zel'dovich Effect observations in concert with X-ray data to measure cosmological parameters. I will discuss the latest direct, SZE+X-ray distance measurements to clusters and the resulting constraints on the Hubble parameter. In addition, I'll compare baryon fraction analyses of large cluster samples carried out using X-ray and SZE observations; the sensitivity to different moments of the intracluster medium density in the SZE and X-ray analyses allows one to use this comparison to study the state of the intracluster medium and test the validity of baryon fraction constraints on \OmegaM.

J.J.M. is a Chandra Fellow supported by grant PF8-1003, awarded through the Chandra Science Center. The Chandra Science Center is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-39073.

If you would like more information about this abstract, please follow the link to http://www.astro.uiuc.edu/~jmohr. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

The author(s) of this abstract have provided an email address for comments about the abstract: jmohr@astro.uiuc.edu

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