Cosmology with Galaxy Clusters and the Cycle of Baryons Across Cosmic Time
Abstract
The X-ray study of hot baryons within galaxy clusters plays a central role in reconstructing the assembly of cosmic structures and tracing the past history of star formation and accretion onto supermassive Black Holes. Outstanding scientific questions opened by Chandra and XMM include: (a) When and how is entropy injected into the inter-galactic medium (IGM)? (b) What is the history of metal enrichment of the IGM? (c) What physical mechanisms determine the presence of cool cores in galaxy clusters? (d) How is the appearance of proto-clusters at z about 2 related to the peak of star formation activity and BH accretion? These questions can be addressed by a large-area X-ray survey, reaching a sensitivity comparable to that of deep Chandra and XMM pointings, but extending over several thousands of square degrees. Such a survey can only be carried out with a Wide-Field X-ray Telescope (WFXT). WFXT surveys will detect huge samples of virialized objects spanning the mass range from sub-groups to the most massive clusters, and extending in redshift to beyond z of 2. These samples will be an excellent dataset for carrying out many traditional cosmological tests using the cluster mass function and power spectrum. Uniquely, WFXT will not only detect clusters but will make detailed X-ray measurements for large numbers of clusters and groups directly from the survey data. Very high quality measurements of the cluster mass function and spatial correlation over a very wide range of masses, spatial scales, and redshifts, will expand the cosmological discovery space, and in particular, will allow searches for departures from the ``concordant'' Lambda-CDM cosmological model. Finding such departures would have far-reaching implications on our understanding of the fundamental physics which govern the Universe.
- Publication:
-
American Astronomical Society Meeting Abstracts #215
- Pub Date:
- January 2010
- Bibcode:
- 2010AAS...21547303F