Related papers: The Morphology-Density relationship in 1<z<2 clust…
We describe a new wide field Hubble Space Telescope survey of the galaxy cluster Cl0024+16 (z~0.4) consisting of a sparse-sampled mosaic of 39 Wide Field and Planetary Camera 2 images which extends to a cluster radius of 5 Mpc. [Abridged]…
Elliptical and S0 galaxies dominate the galaxy population in nearby rich clusters such as Coma. Studies of the evolution of the colors, M/L ratios, and line indices of early-type galaxies indicate that they have been a highly homogeneous,…
The dense environment of galaxy clusters strongly influences the nature of galaxies. Here, we study the cause of the size distribution of a sample of 560 spectroscopic members spanning a wide dynamical range down to 10^8.5 M_sol (log(M)-2)…
The relationship between galaxy size and environment has remained enigmatic, with over a decade of conflicting results. We present one of the first comprehensive studies of the variation of galaxy radius with environment beyond the local…
We use an approach to estimate galaxy morphologies based on an ellipticity (e) vs. Bulge-to-Total ratio (B/T) plane. We have calibrated this plane by comparing with Dressler's classifications. With the aid of our calibration, we have…
We have examined the morphological make-up of X-ray bright groups. The brighter galaxies in these groups exhibit clear morphology-density and morphology-radius relations. The group morphology-density relation is offset from the cluster…
Galaxies with different morphological characteristics likely have different evolutionary histories, such that understanding the mechanisms that drive morphological change can provide valuable insights into the galaxy evolution process.…
In order to assess whether the environment has a significant effect on galaxy sizes, we compare the mass--size relations of cluster and field galaxies in the $0.4 < z < 0.8$ redshift range from the ESO Distant Cluster Survey (EDisCS) using…
We present a morphological study of galaxies in the A901/902 supercluster from the COMBO-17 survey. A total of 570 galaxies with photometric redshifts in the range 0.155 < z_phot < 0.185 are visually classified by three independent…
We explore the evolution of the morphology density relation using the COSMOS-ACS survey and previous cluster studies. The Gini parameter measured in a Petrosian aperture is found to be an effective way of selecting early-type galaxies free…
(Abridged) We analyze the environments and galactic properties (morphologies and star-formation histories) of a sample of 153 close kinematic pairs in the redshift range 0.2 < z < 1 identified in the zCOSMOS-bright 10k spectroscopic sample…
Recent work has shown that the star formation-density relation -- in which galaxies with low star formation rates are preferentially found in dense environments -- is still in place at z~1, but the situation becomes less clear at higher…
Morphology is often used to infer the state of relaxation of galaxy clusters. The regularity, symmetry, and degree to which a cluster is centrally concentrated inform quantitative measures of cluster morphology. The Cluster Lensing and…
We use a complete, unbiased sample of 257 dwarf (10^8 MSun < Mstar < 10^9.5 MSun) galaxies at z < 0.08, in the COSMOS field, to study the morphological mix of the dwarf population in low-density environments. Visual inspection of extremely…
We employ N--body/$3D$ gas dynamic simulations of the formation of galaxy clusters to determine whether cluster X--ray morphologies can be used as cosmological constraints. Confirming the analytic expectations of Richstone, Loeb, \& Turner,…
We analyzed the shapes of Galactic open clusters by the star counting technique with the 2MASS star catalog database. Morphological parameters such as the ellipticity and size have been derived via stellar density distribution, weighed by…
We use a sample of close galaxy pairs selected from the Sloan Digital Sky Survey Data Release 4 (SDSS DR4) to investigate in what environments galaxy mergers occur and how the results of these mergers depend on differences in local galaxy…
The zCOSMOS-bright 10k spectroscopic sample reveals a strong environmental dependence of close kinematic galaxy pair fractions in the redshift range 0.2 < z < 1. The fraction of close pairs is three times higher in the top density quartile…
We study the morphology of galaxy populations of the richest superclusters from the catalogue of superclusters of galaxies in the 2dF Galaxy Redshift Survey using the luminosity density distribution and Minkowski functional V3. We compare…
We present weak gravitational lensing analysis of 22 high-redshift (z >~1) clusters based on Hubble Space Telescope images. Most clusters in our sample provide significant lensing signals and are well detected in their reconstructed…