AAS 207th Meeting, 8-12 January 2006
Session 190 Galaxy Clusters at z $>$ 0.5
Oral, Thursday, 10:00-11:30am, January 12, 2006, Maryland

Previous   |   Session 190   |   Next  |   Author Index   |   Block Schedule

[190.05] Color Bimodality in Galaxy Clusters to z = 1.

Y.-S. Loh, E. Ellingson (University of Colorado, Boulder), H. K. C. Yee (University of Toronto), M. D. Gladders (Carnegie Observatories), Red-Sequence Cluster Survey (RCS) Collaboration

We present the evolution of the color bimodality of galaxy clusters from z = 0.45 to z = 0.95 using a homogeneously selected sample of ~2000 clusters with Bgc, red > 300 (corresponding to Abell Richness Class > 0; comoving density < 10-5 h3 Mpc-3) drawn from the 92 deg2 Red-Sequence Cluster Survey (RCS). The red fraction of galaxies decreases as a function of redshift for all cluster-centric radii, consistent with the Butcher-Oemler (1978) effect. The color-radius relation is also well established at all redshifts, with the red fraction decreasing toward the cluster outskirts. We detected a more rapid rate of redshift evolution in the red fraction at the cluster core compared to the cluster outskirts, suggesting that the higher galaxy infall rate at earlier times contributes significantly to the Butcher-Oemler effect seen in these clusters. This work is partially funded by NSF AST 0206154 and NASA.

If you would like more information about this abstract, please follow the link to http://casa.colorado.edu/~yeongloh/AAS/BO.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 190   |   Next

Bulletin of the American Astronomical Society, 37 #4
© 2005. The American Astronomical Soceity.