NOAO >   Observing Info >   Approved Programs >   2006B-0355

# Proposal Information for 2006B-0355

PI: Kenneth Rines, Yale/YCAA, krines@astro.yale.edu
Address: Yale Center for Astronomy and Astrophysics, PO Box 208121, New Haven, CT 06511, USA

CoI: Thomas Reiprich, Universitat Bonn, Germany
CoI: Alexey Vikhlinin, CfA/IKI
CoI: Andrey Kravtsov, U of Chicago
CoI: Hernan Quintana, P.U.C., Chile
CoI: Sune Toft, ESO, Germany

Title: Cluster Scaling Relations, Star Formation Efficiency, and Dark Energy

Abstract: We propose to complete near-infrared K_s-band imaging of a unique sample of 41 X-ray selected galaxy clusters at moderate to high redshift (z=0.35-0.90) with approved \em Chandra observations. We will measure their stellar masses and study their galaxy populations over the entire virial regions and into the infall regions. Both semi-analytic models and simulations incorporating radiative cooling and galaxy formation overpredict the stellar masses of clusters by a factor of 2-3. Our photometry will measure the stellar masses and hence the (integrated) star formation efficiency and its dependence on both redshift and cluster mass. These data will also establish cluster scaling relations and their evolution at z=0.35-0.90, robustly quantify the down-sizing'' effect and its dependence on mass, study the evolution of cluster galaxies from the infall regions to their cores, measure the halo occupation function and its evolution, and provide important inputs into future cluster surveys which will probe dark energy. A large, complete sample is required to test systematics in cluster scaling relations with both mass and redshift. These data will also be used to understand the history of star formation in clusters with scheduled \em Spitzer observations and provide efficient target selection for future spectroscopy.

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 NOAO >   Observing Info >   Approved Programs >   2006B-0355