Related papers: Substructure in Clusters and Central Galaxy Peculi…
We present an analysis of the velocity space of a sample of globular clusters (GC) with absolute proper motions. The vertical component of the velocity is found to be correlated with luminosity and galactocentric radius. We divided the…
The method for detection of the galaxy cluster rotation based on the study of distribution of member galaxies with velocities lower and higher of the cluster mean velocity over the cluster image is proposed. The search for rotation is made…
Galaxy cluster peculiar velocities can be inferred from high-sensitivity, high-resolution multiple-frequency observations in the 30 to 400 GHz range. While galaxy cluster counts and power spectra are sensitive to the growth factor, peculiar…
A clustering analysis is performed on two samples of $\sim 600$ faint galaxies each, in two widely separated regions of the sky, including the Hubble Deep Field. One of the survey regions is configured so that some galaxy pairs span angular…
We present a statistical study of substructure within a sample of LCDM clusters and galaxies simulated with up to 25 million particles. With thousands of subhalos per object we can accurately measure their spatial clustering and velocity…
We want to study how the velocity segregation and the radial profile of the velocity dispersion depend on the prominence of the brightest cluster galaxies (BCGs). We divide a sample of 102 clusters and groups of galaxies into four bins of…
There has been plenty of observational evidence of cluster galaxy evolution. However, it has been difficult to identify the origin of the cluster galaxy evolution. Here we show that gravitational interaction/friction between galaxies is the…
The distribution on the sky of clusters of galaxies shows significant association with relatively nearby, large, active galaxies. The pattern is that of clusters paired equidistant across a central galaxy with the apparent magnitudes and…
We study the substructure statistics of a representative sample of galaxy clusters by means of two currently popular substructure characterisation methods, power ratios and centroid shifts. We use the 31 clusters from the REXCESS sample,…
With the help of a statistical parameter derived from optical spectra, we show that the current star formation rate of a galaxy, falling into a cluster along a supercluster filament, is likely to undergo a sudden enhancement before the…
We present a simple model for the shape of the distribution function of galaxy peculiar velocities. We show how both nonlinear and linear theory terms combine to produce a distribution which has an approximately Gaussian core with…
We study the systematic bias introduced when selecting the spectroscopic redshifts of brighter cluster galaxies to estimate the velocity dispersion of galaxy clusters from both simulated and observational galaxy catalogues. We select…
We use catalogues of superclusters of galaxies from the 2dF Galaxy Redshift Survey to study the properties of galaxies in superclusters. We compare the properties of galaxies in high and low density regions of rich superclusters, in poor…
Massive galaxy clusters are now found as early as 3 billion years after the Big Bang, containing stars that formed at even earlier epochs. The high-redshift progenitors of these galaxy clusters, termed 'protoclusters', are identified in…
Numerous methods for finding clusters at moderate to high redshifts have been proposed in recent years, at wavelengths ranging from radio to X-rays. In this paper we describe a new method for detecting clusters in two-band optical/near-IR…
We present the results of a redshift survey of both cluster and intercluster galaxies in the central part of the Shapley Concentration, the richest supercluster of clusters in the nearby Universe, consisting of ~2000 radial velocities. We…
Young stars form on a wide range of scales, producing aggregates and clusters with various degrees of gravitational self-binding. The loose aggregates have a hierarchical structure in both space and time that resembles interstellar…
A significant fraction of clusters of galaxies are observed to have substructure, which implies that merging between clusters and subclusters is a rather common physical process of cluster formation. It still remains unclear how cluster…
We measure the central stellar velocity dispersion function for quiescent galaxies in a set of nine northern clusters in the redshift range $0.18 < z < 0.29$ and with strong lensing arcs in Hubble Space Telescope images. The velocity…
Observations of early-type dwarf galaxies in clusters often show that cluster dwarf members have significantly higher velocities and less symmetric distributions than cluster giant ellipticals, suggesting that these dwarfs are recently…