相关论文: Cluster Evolution in the Wide Angle ROSAT Pointed …

The ``MORPHS'' group has completed the cataloging, parameterization, and morphological classification of ~2000 galaxies in 10 rich clusters from 0.36 < z < 0.56. From a weak lensing analysis using these data, which compares the X-ray…

We briefly review our current knowledge of the space density of distant X-ray clusters as measured by several ROSAT serendipitous surveys. We compare old and new determinations of the cluster X-ray Luminosity Function (XLF) at increasing…

We present the X-ray Luminosity Function (XLF) of the ROSAT Deep Cluster Survey (RDCS) sample over the redshift range 0.05-0.8. Our results are derived from a complete flux-limited subsample of 70 galaxy clusters, representing the brightest…

We have embarked on a survey of ROSAT PSPC archival data with the aim of detecting all significant surface brightness enhancements due to sources in the innermost 15 arcmin of the PSPC field of view (0.5-2.0 keV). This project is part of…

We consider a sample of 51 distant galaxy clusters at 0.15<z<0.9 (<z> about 0.3), each cluster having at least 10 galaxies with available redshift in the literature. We select member galaxies, analyze the velocity dispersion profiles, and…

We consider a sample of about 50 distant galaxy clusters at z>0.15 (<z> about 0.3), each cluster having at least 10 galaxies with available redshift in the literature. We select member galaxies, analyze the velocity dispersion profiles, and…

We present a deep UBI CCD survey using the Palomar 5-m telescope of a sample of high X-ray luminosity, distant clusters selected from the ROSAT All-Sky Survey. The 10 clusters lie at z=0.22-0.28, an era where evolutionary effects have been…

We present in catalog form the optical identifications for objects from the first phase of the Wide Angle ROSAT Pointed Survey (WARPS). WARPS is a serendipitous survey of relatively deep, pointed ROSAT observations for clusters of galaxies.…

We present the results of a weak lensing survey of six high-redshift (z > 0.5), X-ray selected clusters of galaxies. We have obtained ultra-deep R-band images of each cluster with the Keck Telescope, and have measured a weak lensing signal…

We present first results from the MAssive Cluster Survey (MACS), a new large-scale X-ray survey designed to find and characterize very massive, distant clusters of galaxies. Based on X-ray detections in the ROSAT All-Sky Survey, MACS aims…

We present an optical analysis of a sample of 11 clusters built from the EXCPRES sample of X-ray selected clusters at intermediate redshift (z ~ 0.5). With a careful selection of the background galaxies we provide the mass maps…

We investigate the galaxy populations in seven X-ray selected, intermediate-redshift groups (0.2<z<0.6). Overall, the galaxy populations in these systems are similar to those in clusters at the same redshift; they have large fractions of…

Evidence is presented for a recent evolution of the relaxation processes in clusters of galaxies, using large optical and X-ray cluster samples. The criteria of the cluster relaxation used are the cluster ellipticity, the ICM temperature…

We present the z = 0.3 - 0.7 cluster X-ray luminosity function (XLF) determined from the Southern SHARC (Serendipitous High-redshift Archival ROSAT Cluster) survey. Over the luminosity range L ~ (0.3 - 3) x 10^44 erg/s (0.5 - 2.0 keV) the…

We present results of a weak gravitational lensing survey of six X-ray selected high-redshift clusters of galaxies. We find that the masses of the clusters derived from weak lensing are comparable to those derived from the X-ray…

We use new models of stellar population synthesis to estimate the fraction of stars formed during the last major bursts of star formation in E/S0 galaxies in low-redshift clusters ($z\simlt0.4$) from the spectral signatures of…

Galaxy clusters at high redshift present a superb opportunity to study galaxy evolution, with large galaxy samples at fixed distances. Several lines of evidence point towards large formation redshifts and passive evolution for cluster…

The deepest region of the ROSAT All-Sky Survey, at the North Ecliptic Pole, has been studied to produce a complete and unbiased X-ray selected sample of clusters of galaxies. This sample is used to investigate the nature of cluster…

Galaxy groups and low-mass clusters provide important laboratories in which to study X-ray gas physics and the interplay between galaxy evolution and environmental effects. The X-ray Multi-Mirror (XMM) Large Scale Structure (LSS) survey has…

Our understanding of the cosmic history of galaxy clusters has recently been enhanced due to an extensive series of observations including faint spectroscopic data (especially those obtained at the Keck Observatory), deep optical and NIR…