Related papers: Cluster versus POTENT Density and Velocity Fields:…
We analyze the density profiles and virial radii for a sample of 90 nearby clusters, using galaxies with available redshifts and positions. Each cluster has at least 20 redshifts measured within an Abell radius, and all the results come…
We present a statistical comparison of three different estimates of cluster mass, namely, the dynamical masses obtained from the velocity dispersion of optical galaxies, the X-ray masses measured from the temperature of X-ray emitting gas…
The power spectrum (PS) of mass density fluctuations, in the range $0.05 \leq k \leq 0.2 \ihmpc$, is derived from the Mark III catalog of peculiar velocities of galaxies, independent of ``biasing". It is computed from the density field as…
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…
The morphology of galaxy clusters reflects the epoch at which they formed and hence depends on the value of the mean cosmological density, Omega. Recent studies have shown that the distribution of dark matter in clusters can be mapped from…
We test the ability of strong lensing data to constrain the size of a central core in the dark matter halos of galaxy clusters, using Abell 611 as a prototype. Using simulated data, we show that modeling a cluster halo with ellipticity in…
We use N-body simulations to study the shape of mean cluster density and velocity profiles formed via gravitational instability. The dependence of the final structure on both cosmology and initial density field is examined, using a grid of…
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 <=…
The large-scale structure in the distribution of galaxies is thought to arise from the gravitational instability of small fluctuations in the initial density field of the universe. A key test of this hypothesis is that superclusters of…
We present the results of the analysis of the internal velocity dispersions, \sigma_v, for the CNOC sample of distant galaxy clusters, based on an interlopers removal algorithm, which is different from that originally applied by Carlberg et…
We present 83 new galaxy radial velocities in the field of 18 APM clusters with redshifts between 0.06 and 0.13. The clusters have Abell identifications and the galaxies were selected within 0.75 h$^{-1}$Mpc in projection from their…
We study the rms peculiar velocity of clusters as a convenient statistic to put constraints on cosmological models. This statistic is easy to compute theoretically given a model for the power spectrum; we show that with some assumptions it…
We generate the 2-dimensional high-resolution density field of galaxies of the Early Data Release of the Sloan Digital Sky Survey and the Las Campanas Redshift Survey with a smoothing length 0.8 Mpc/h to extract clusters and groups of…
We present a self consistent nonparametric model of the local cosmic velocity field based on the density distribution in the PSCz redshift survey of IRAS galaxies. The error analysis, carried out on mock PSCz catalogues constructed from…
Measurements of the cosmological density parameter Omega using techniques that exploit the gravity-induced motions of galaxies constrain, in linear perturbation theory, the degenerate parameter combination beta = Omega^{0.6}/b, where the…
We analyze subsamples of Abell and ACO cluster catalogs, in order to study the spatial properties of the large scale matter distribution. The subsamples analyzed are estimated to be nearly complete and are the standard ones used in the…
Using third-order perturbation theory, we derive a relation between the mean divergence of the peculiar velocity given density and the density itself. Our calculations assume Gaussian initial conditions and are valid for Gaussian filtering…
We present two new dynamical tests of the biasing hypothesis. The first is based on the amplitude and the shape of the galaxy-galaxy correlation function, $\xi_g(r)$, where $r$ is the separation of the galaxy pair. The second test uses the…
We apply a new algorithm, called the Unbiased Minimal Variance (hereafter UMV) estimator, to reconstruct the cosmic density and peculiar velocity fields in our local universe from the SEcat catalog of peculiar velocities comprising both…
We test an analytic model for the two-point correlations of galaxy clusters in redshift space using the Hubble Volume N-body simulations. The correlation function of clusters shows no enhancement along the line of sight, due to the lack of…