The Color Bimodality in Galaxy Clusters since z = 0.9

Abstract

We present the evolution of the color-magnitude distribution of galaxy clusters from z = 0.45 to z = 0.9 using a homogeneously selected sample of ~1000 clusters drawn from the Red-Sequence Cluster Survey (RCS). The red fraction of galaxies decreases as a function of increasing redshift for all cluster-centric radii, consistent with the Butcher-Oemler effect, and suggesting that the cluster blue population may be identified with newly infalling galaxies. We also find that the red fraction at the core has a shallower evolution compared with that at the cluster outskirts. Detailed examination of the color distribution of blue galaxies suggests that they have colors consistent with normal spirals and may redden slightly with time. Galaxies of starburst spectral type contribute less than 5% of the increase in the blue population at high redshift, implying that the observed Butcher-Oemler effect is not caused by a unobscured starbursts, but is more consistent with a normal coeval field population.

27 pages, 7 figures, accepted for publication in the ApJ

References in corpus (4)

• The DEEP2 Galaxy Redshift Survey: The Role of Galaxy Environment in the Cosmic Star-Formation History
• The redshift evolution of early-type galaxies in COSMOS: Do massive early-type galaxies form by dry mergers?
• The Red-Sequence Luminosity Function in Galaxy Clusters since z~1
• Spectroscopy of moderately high-redshift RCS-1 clusters

Cited by in corpus (4)

• The Assembly of Galaxy Clusters
• Spitzer/MIPS 24um Observations of Galaxy Clusters: An Increasing Fraction of Obscured Star-forming Members from z=0.02 to z=0.83
• The Evolution of Dusty Star Formation and Stellar Mass Assembly in Clusters: Results from the IRAC 3.6um, 4.5um, 5.8um and 8.0um Cluster Luminosity Functions
• Central and Satellite Colors in Galaxy Groups: A Comparison of the Halo Model and SDSS Group Catalogs