Related papers: An extension of the SHARC survey
We report on the progress of our search for serendipitous distant X-ray galaxy clusters in the ROSAT PSPC pointed observations archive. The initial aim of our work is to measure the X-ray luminosity function of clusters down to 4 x 10^-14…
(Abridged) Distant galaxy clusters provide important tests of the growth of large scale structure in addition to highlighting the process of galaxy evolution in a consistently defined environment at large look back time. We present a sample…
We present the results of a search for X--ray luminous distant clusters of galaxies. We found extended X--ray emission characteristic of a cluster towards two of our candidate clusters of galaxies. They both have a luminosity in the ROSAT…
We present the Bright SHARC (Serendipitous High-Redshift Archival ROSAT Cluster) Survey, which is an objective search for serendipitously detected extended X-ray sources in 460 deep ROSAT PSPC pointings. The Bright SHARC Survey covers an…
We describe the initial results of a programme to detect and identify extended X-ray sources found serendipitously in XMM-Newton observations. We have analysed 186 EPIC-PN images at high galactic latitude with a limiting flux of $1\times…
Context: Galaxy clusters at high redshift are important to test cosmological models and models for the growth of structure. They are difficult to find in wide-angle optical surveys, however, leaving dedicated follow-up of X-ray selected…
In the construction of an X-ray selected sample of galaxy clusters for cosmological studies, we have assembled a sample of 495 X-ray sources found to show extended X-ray emission in the first processing of the ROSAT All-Sky Survey. The…
Observational studies of cluster evolution over moderate redshift ranges (to z ~ 1) are a powerful tool for constraining cosmological parameters, yet a comprehensive knowledge of the properties of these clusters has been hitherto…
High redshift (z >~ 1) clusters are ideal probes to study the formation and evolution of large scale structures and galaxies in the universe. A 10-m class ground based telescope, X-ray observatories (Chandra, XMM-Newton) and HST/ACS are…
We present a galaxy cluster survey based on XMM-Newton observations that are located in Stripe 82 of the Sloan Digital Sky Survey (SDSS). The survey covers an area of 11.25 deg$^2$. The X-ray cluster candidates were selected as…
We present X-ray and optical spectroscopic observations of twelve galaxy groups and clusters identified within the XMM Large-Scale Structure (LSS) survey. Groups and clusters are selected as extended X-ray sources from a 3.5 deg2 XMM image…
Inspired by the discovery of the Phoenix cluster by the South Pole Telescope team, we initiated a search for other massive clusters of galaxies missing from the standard X-ray catalogs. We began by identifying 25 cluster candidates not…
We present five newly found galaxy clusters at z>0.6 from the XMM Large-Scale Structure Survey (XMM-LSS). All five objects are extended X-ray sources in the XMM images. For three of them we have sufficient spectroscopically confirmed member…
Based on the ROSAT All-Sky Survey we are constructing a sample of the X-ray brightest galaxy clusters for cosmological studies. We have already completed the compilation of a sample of about 1000 clusters in the sky excluding a 40 degree…
We present a survey of serendipitous extended X-ray sources and optical cluster candidates from the Chandra Multi-wavelength Project (ChaMP). Our main goal is to make an unbiased comparison of X-ray and optical cluster detection methods. In…
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…
The first systematic study of the serendipitous X-ray source density around 10 high z (0.24<z<1.2) clusters performed with Chandra is presented. A factor \~2 overdensity has been found in 4 cluster fields. The result is statistically highly…
We present results of an initial search for clusters of galaxies at z~1 and above, using data from 2.9 square degrees of XMM-Newton images. By selecting weak potentially extended X-ray sources with faint or no identifications in deep,…
The ~1 Ms Chandra Deep Field North observation is used to study the extended X-ray sources in the region surrounding the Hubble Deep Field North (HDF-N), yielding the most sensitive probe of extended X-ray emission at cosmological distances…
We present the revised catalog of galaxy clusters detected as extended X-ray sources in the 160 Square Degree ROSAT Survey, including spectroscopic redshifts and X-ray luminosities for 200 of the 201 members. The median redshift is z~0.25…