Related papers: Optical Radii of Galaxy Clusters
We present the distribution of virial masses for nearby galaxy clusters, as obtained from a data-set of 75 clusters, each having at least 20 galaxy members with measured redshifts within 1 Abell radius. After having accounted for problems…
We present the results of a study for galaxy orbits in galaxy clusters using a spectroscopic sample of galaxies in Sloan Digital Sky Survey (SDSS) and 2dF Galaxy Redshift Survey (2dFGRS). We have determined the member galaxies of Abell…
We investigate the galaxy population in a field of the Perseus cluster that roughly covers the virial radius of the cluster. The galaxies were selected on Schmidt CCD images in B and H alpha in combination with SDSS images. We present a…
The morphology of clusters of galaxies may be described with a set of parameters which contain information about the formation and evolutionary history of these systems. In this paper we present a preliminary study of the morphological…
We have measured the surface density of galaxies toward 14 X-ray-selected cluster candidates at redshifts greater than z=0.46, and we show that they are associated with rich galaxy concentrations. We find that the clusters range between…
We report the first results of a long term program aimed at investigating the photometric properties of the cores of Abell and X-ray selected (EMSS, \cite{emss}) clusters of galaxies. We observed 77 clusters of galaxies in the redshift…
The systematic errors in the virial mass-to-light ratio, M_v/L, of galaxy clusters as an estimator of the field M/L value are assessed. We overlay 14 clusters in redshift space to create an ensemble cluster which averages over substructure…
We study the rotational motion of the galaxy cluster Abell 2107 at redshift z = 0.04 and its connection to nearby large-scale structures using a large amount of spectroscopic redshift data. By combining 978 new redshifts from the…
We analyze photometric properties of 1384 cluster galaxies as a function of the normalized distance to cluster center. These galaxies were selected in the central region ($r/r_{200} \leq$ 0.8) of 14 southern Abell clusters chosen from the…
We present an analysis of the spatial orientations of galaxies in the 247 optically selected rich Abell clusters, having in the considered area at least 100 members. We investigated the relation between angles giving information about…
We present two catalogues of galaxies in the direction of the rich cluster \a85. The first one includes 4,232 galaxies located in a region $\pm 1^\circ$ from the cluster centre. It has been obtained from a list of more than 25,000 galaxy…
We have reanalyzed a data set of 99 low redshift ($ z < 0.1 $) Abell clusters and determined their shapes. For this, three different measures are used. We use Monte-Carlo simulations to investigate the errors in the methods. The corrected…
We analyze the internal dynamics of 43 non-interacting clusters which are selected from the 2dF Galaxy Redshift Survey 100k public release. We join together the 43 clusters into an ensemble cluster by appropriately scaling their galaxy…
The core structure of galaxy clusters is fundamentally important. Even though self-gravitating systems have no stable equilibrium state due to their negative heat capacity, numerical simulations find density profiles which are universal in…
We present the results from an extensive spectroscopic survey of the central region of the nearby galaxy cluster Abell 2199 at $z=0.03$. By combining 775 new redshifts from the MMT/Hectospec observations with the data in the literature, we…
We evaluate in a homogeneous way the optical masses of 170 nearby clusters (z< 0.15). The sample includes both data from the literature and the new ENACS data (Katgert et al. 1996, 1998). On the assumption that mass follows the galaxy…
We investigate the distribution of superclusters and voids using a new catalogue of superclusters of rich clusters of galaxies which extends up to a redshift of z=0.12. The new catalogue contains 220 superclusters of rich clusters, of which…
Recent simulations have indicated that the dark matter halos of galaxy clusters should feature steep density jumps near the virial radius. Since the member galaxies are expected to follow similar collisionless dynamics as the dark matter,…
We have conducted an automated search for galaxy clusters within a contiguous 16 square degree I-band survey in the north Galactic hemisphere. A matched filter detection algorithm identifies 444 cluster candidates in the range 0.2 <= z <=…
We report an analysis of the dynamical structure of clusters of galaxies from a survey of photometric and spectroscopic observations in the fields of southern Abell Clusters. We analyze the galaxy velocity field in extended regions up to 7…