相关论文: The Slope of the Cluster Elliptical Red Sequence: …
We present a comprehensive analysis of the stellar population properties (age, metallicity and the alpha-element enhancement [E/Fe]) and morphologies of red-sequence galaxies in 24 clusters and groups from z~0.75 to z~0.45. The dataset,…
The ellipticities and alignments of clusters of galaxies, and their evolution with redshift, are examined in the context of a Lambda-dominated cold dark matter cosmology. We use a large-scale, high-resolution N-body simulation to model the…
We present a study of the color evolution of elliptical and S0 galaxies in six clusters of galaxies inside the redshift range 0.78 < z < 1.27. For each cluster, we used imaging from the Hubble Space Telescope to determine morphological…
Two-dimensional surface photometry derived from Hubble Space Telescope imaging is presented for a sample of 225 early-type galaxies (assumed to be cluster members) in the fields of 9 clusters at redshifts $0.17 < z < 1.21$. The 94 luminous…
It is shown that the number of members, $N_A$, and the linear radius of the Abell clusters at $z<0.18$ increase with redshift. The increase is caused by observational selection: the number of rich and large clusters is small in the nearby…
New ground-based and HST observations of distant clusters make it possible to trace the history of E/S0 galaxies to lookback times of ~10 $h_{50}^{-1}$ Gyr. The data strongly favor a scenario in which cluster ellipticals formed very early…
We have carried out a joint photometric and structural analysis of red sequence galaxies in four clusters at a mean redshift of z ~ 1.25 using optical and near-IR HST imaging reaching to at least 3 magnitudes fainter than $M^*$. As…
Cluster ellipticals are often thought to be among the oldest galaxies in the universe, with the bulk of their stellar mass formed at early cosmic epochs. I review recent observations of color evolution in early-type cluster galaxies at high…
In hierarchical models of galaxy formation, ellipticals form from the merging of disk galaxies drawn together by gravity as their surrounding dark halos coalesce. Using semi-analytic techniques, we are able to follow the merging, star…
We apply detailed observations of the Color-Magnitude Relation (CMR) with the ACS/HST to study galaxy evolution in eight clusters at z~1. The early-type red sequence is well defined and elliptical and lenticular galaxies lie on similar…
Galaxies arrive on the red sequences of clusters at high redshift ($z>1$) once their star formation is quenched and evolve passively thereafter. However, we have previously found that cluster red sequence galaxies (CRSGs) undergo…
We present the ellipticity distribution and its evolution for early-type galaxies in clusters from z~0.8 to z~0, based on the WIde-field Nearby Galaxy-cluster Survey (WINGS)(0.04<z<0.07), and the ESO Distant Cluster Survey…
Combined HST, X-ray, and ground-based optical studies show that clusters of galaxies are largely "in place" by $z \sim 1$, an epoch when the Universe was less than half its present age. High resolution images show that elliptical, S0, and…
We investigate the dependence of ellipticities of clusters of galaxies on cosmological parameters using large-scale cosmological simulations. We determine cluster ellipticities out to redshift unity for LCDM models with different mean…
The study of galaxy morphology is fundamental to understand the physical processes driving the structural evolution of galaxies. It has long been known that dense environments host high fractions of early-type galaxies and low fractions of…
The morphological types of galaxies in nine clusters in the redshift range 0.1<z<0.25 are derived from very good seeing images taken at the NOT and the La Silla Danish telescopes. With the purpose of investigating the evolution of the…
Velocity dispersions $\sigma$ and Mg absorption line-strengths Mg$_b$ have been measured for a sample of 16 ellipticals in 3 clusters at a redshift of 0.37. Like local cluster ellipticals, these objects show a correlation between Mg$_b$ and…
We review the observational evidence showing that luminous cluster elliptical galaxies are old stellar systems, undergoing mostly passive stellar evolution up to redshift $z\approx 1$, with approximate coeval epoch of formation. This…
We investigate the evolution of the optical and near-infrared colour-magnitude relation in an homogeneous sample of massive clusters from z = 1 to the present epoch. By comparing deep Hubble Space Telescope ACS imaging of X-ray selected…
Measurements of galaxy clustering are now becoming possible over a range of redshifts out to z=3. We use a semi-analytic model of galaxy formation to compute the expected evolution of the galaxy correlation function with redshift. We…