AAS 195th Meeting, January 2000
Session 10. Multiwavelength Observations of Clusters of Galaxies
Display, Wednesday, January 12, 2000, 9:20am-6:30pm, Grand Hall

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[10.11] The Stanford Cluster Search (StaCS): Towards an Unbiased Sample of Rich Clusters at Intermediate Redshift

J.A. Willick, K.L. Thompson (Stanford University)

We describe StaCS, a program to identify intermediate redshift (0.3 \le z \le 1.0) rich clusters of galaxies from deep, wide- field CCD images, and to follow-up these identifications with extensive spectroscopy at the Hobby-Eberly Telescope (HET). The clusters are identified using a matched-filter algorithm applied to images acquired as part of the Lawrence Berkeley Laboratory Supernova Cosmology Project (SCP). The SCP imaging data base covers approximately 25 square degrees of sky to a depth mR= 23.5 or fainter. Follow-up observations from the 8 meter class HET will measure cluster redshifts and velocity dispersions. The velocity dispersions will in turn yield mass estimates, which we will seek to confirm with future X-ray and gravitational lensing measurements. Our measurements will enable us to determine the comoving number density of clusters as a function of mass and redshift, n(M,z). Comparison with theoretical predictions, from the Press-Schechter formalism and related approaches, will allow a determination of the mass density parameter \OmegaM, and the rms density fluctuation on an 8 Mpc scale, \sigma8, to 15% accuracy or better, and a test of the hypothesis that the primordial density fluctuations are Gaussian. In a companion poster (Thompson & Willick), we describe the first spectroscopic results from the HET.

This work is supported in part by the Research Corporation.

If you would like more information about this abstract, please follow the link to http://astro.stanford.edu/jeffw/StaCS.html. 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. [Previous] | [Session 10] | [Next]