Related papers: The Color Bimodality in Galaxy Clusters since z = …
Using cosmological N-body simulations of critical (SCDM) and open ($\Omega = 0.3$, OCDM) cold dark matter models, we investigate evolution of cluster galaxies. From our numerical simulation, we construct merging history trees of the…
We previously reported a significant clustering of red galaxies (R-K=3.5--6) around the radio-loud quasar B2 1335+28 at z=1.086. In this paper, we establish the existence of a rich cluster at the quasar redshift, and study the properties of…
The fraction of star-forming galaxies in rich clusters of galaxies increases rapidly with the redshift. This is interpreted as the result of a rapid evolution of cluster galaxies, though its mechanism is not yet clear. One hypothesis is…
We show how the observed bimodality in the color distribution of galaxies can be explained in the framework of the hierarchical clustering picture in terms of the interplay between the properties of the merging histories and the…
Using traditional morphological classifications of galaxies in 10 intermediate-redshift (z~0.5) clusters observed with WFPC-2 on the Hubble Space Telescope, we derive relations between morphology and local galaxy density similar to that…
Globular cluster systems in most large galaxies display bimodal color and metallicity distributions, which are frequently interpreted as indicating two distinct modes of cluster formation. The metal-rich (red) and metal-poor (blue) clusters…
Using wide-field HST/WFPC2 imaging and extensive Keck/LRIS spectroscopy, we present a detailed study of the galaxy populations in MS2053--04, a massive, X-ray luminous cluster at z=0.5866. Analysis of 149 confirmed cluster members shows…
Understanding the clustering of galaxies has long been a goal of modern observational cosmology. Utilizing our photometric redshift technique a volume limited sample containing more than 2 million galaxies is constructed from the SDSS…
Using a cosmological dark matter simulation of a galaxy-cluster halo, we follow the temporal evolution of its globular cluster population. To mimic the red and blue globular cluster populations, we select at high redshift $(z\sim 1)$ two…
A recent paper (Burke, Collins & Mann 2000) presents the analysis of the K-band Hubble diagram of 76 brightest cluster galaxies (BCGs) in X-ray clusters and shows that the properties of BCGs depend on the X-ray luminosity (Lx) of their host…
We present first measurements of the evolution of the scatter of the cosmic average early-type galaxy color-magnitude relation (CMR) from z=1 to the present day, finding that it is consistent with models in which galaxies are constantly…
We explore the behavior of the blue galaxy fraction over the redshift range 0.75 <= z <= 1.3 in the DEEP2 Survey, both for field galaxies and for galaxies in groups. The primary aim is to determine the role that groups play in driving the…
We analyze the clustering of red and blue galaxies from four samples spanning a redshift range of 0.4<z<2.0 to test the various scenarios by which galaxies evolve onto the red sequence. The data are taken from the UKIDSS Ultra Deep Survey,…
In the six billion years between redshifts z=1 and z=0.1, galaxies change due to the aging of their stellar populations, the formation of new stars, and mergers with other galaxies. Here I explore the relative importance of these various…
The dependence of galaxy star formation activity on environment - especially in clusters - at high redshift is still poorly understood, as illustrated by the still limited number of z>1.4 clusters on the one hand, and by the still debated…
We use the UKIDSS Ultra-Deep Survey to trace the evolution of galaxy clustering to z = 3. Using photometric redshifts derived from data covering the wavelength range 0.3 - 4.5 um we examine this clustering as a function of absolute K-band…
We present a study of the luminosity and color properties of galaxies selected from a sample of 57 low-redshift Abell clusters. We utilize the non-parametric dwarf-to-giant ratio (DGR) and the blue galaxy fraction (fb) to investigate the…
In this poster, we present new results on narrow band photometry for A2218 ($z$=0.18) and A2125 ($z$=0.25), two clusters with similar redshifts, but very different cluster properties. A2218 is a dense, elliptical-rich cluster (Bautz-Morgan…
We investigate the origin of the color-magnitude relation (CMR) observed in cluster galaxies by using a combination of a cosmological N-body simulation of a cluster of galaxies and a semi-analytic model of galaxy formation. The departure of…
The K-band Hubble diagram for a sample of brightest cluster galaxies (BCGs) in the redshift range 0<z<1 shows a very small scatter (0.3 magnitudes r.m.s). The BCGs exhibit very little luminosity evolution in this redshift range: if q_0=0.0…