Related papers: RX J0848+4456: Disentangling a Moderate Redshift C…
We present here an efficient method for selecting high luminosity and massive high redshift clusters of galaxies, crucially important tools in cosmology. By selecting bright and extremely X-ray loud (high F(X)/F(V)) sources, we were able to…
At z=0.809, RXJ1716.6+6708 is the second most distant X-ray selected cluster so far published and the only one with a large number of spectroscopically determined cluster member velocities. The optical morphology of RXJ1716.6+6708 resembles…
We present an optical study of the strong lensing galaxy cluster MS 0440.5$+$0204 at $z=0.19593$, based on CFHT/MegaCam g', r'-photometry and GMOS/Gemini and CFHT/MOS/SIS spectroscopy in a broader area compared to previous works. We have…
We report the discovery of CXOU J191100-595621 and CXOU J191012-595619, two galaxy clusters serendipitously detected in the direction of globular cluster NGC 6752, based on archival {\it Chandra} observations with a total exposure time of…
We present results from Chandra observations of SDSS J1004+4112, a strongly lensed quasar system with a maximum image separation of 15". All four bright images of the quasar, as well as resolved X-ray emission originating from the lensing…
We analyze the seldomly discussed lensing effects expected in low-z clusters (z = 0.05-0.15), using as an example the bright arc (z=0.073) discovered by Campusano and Hardy(1996) near the dominant cD galaxy of the cluster Abell 3408…
We present a detailed analysis of Chandra X-ray observations of the lensing cluster of galaxies CL0024+17 at z=0.395. We found that the radial temperature profile is consistent with being isothermal out to ~600 kpc and that the average…
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 a weak-lensing analysis of the z=1.4 galaxy cluster XMMU J2235.3-2557, based on deep Advanced Camera for Surveys images. Despite the observational challenge set by the high redshift of the lens, we detect a substantial lensing…
We present results from a 100 ks XMM-Newton observation of galaxy cluster XLSSC 122, the first massive cluster discovered through its X-ray emission at $z\approx2$. The data provide the first precise constraints on the bulk thermodynamic…
In the accretion-driven growth scenario, part of the intracluster light is formed in the group environment. We report the serendipitous discovery of a group of galaxies with signs of diffuse light in the foreground of the known galaxy…
We present a weak-lensing analysis of the galaxy cluster CL J1226+3332 at z=0.89 using Hubble Space Telescope Advanced Camera for Surveys images. The cluster is the hottest (>10 keV), most X-ray luminous system at z>0.6 known to date. The…
We present the results of a pointed ROSAT PSPC observation of the cluster A3558 which is part of the core of the Shapley Concentration. The X-ray brightness distribution can be fitted as the sum of an elliptical King law, with a major core…
We present an extensive spectroscopic follow-up campaign of 29 strong lensing (SL) selected galaxy clusters discovered primarily in the Second Red-Sequence Cluster Survey (RCS-2). Our spectroscopic analysis yields redshifts for 52…
We present XMM-Newton results on the spatially resolved temperature profiles of eight massive galaxy clusters of a volume-limited sample at redshifts $z\sim0.3$ (REFLEX-DXL sample) and an additional luminous cluster at $z=0.2578$, selected…
We report the discovery of a cluster of galaxies in the field of UM425, a pair of quasars separated by 6.5arcsec. Based on this finding, we revisit the long-standing question of whether this quasar pair is a binary quasar or a…
We present a novel method to estimate accurate redshifts of star-forming galaxies by measuring the flux ratio of the same emission line observed through two adjacent narrow-band filters. We apply this method to our NB912 and new NB921 data…
We present strong-lensing analyses of three galaxy clusters, RXJ2129.4+0009 (z=0.235), MS0451.6-0305 (z=0.55), and MACSJ2129.4-0741 (z=0.589), using the powerful combination of Hubble Space Telescope (HST) multi-band observations, and…
We model the total mass and galactic substructure in the strong lensing galaxy cluster MACS J0138.0-2155 using a combination of Chandra X-ray data, Multi-Unit Spectroscopic Explorer (MUSE) spectroscopy, and Hubble Space Telescope imaging.…
The ROSAT-ESO Flux Limited X-ray (REFLEX) galaxy cluster survey and the 2dF Galaxy Redshift Survey (2dFGRS) respectively comprise the largest, homogeneous X-ray selected cluster catalogue and completed galaxy redshift survey. In this work…