Related papers: Position Angles and Alignments of Galaxy Clusters
Clusters of galaxies are sensitive to the most nonlinear peaks in the cosmic density field. The weak gravitational lensing of background galaxies by clusters can allow us to infer their masses. However, galaxies associated with the local…
We present a catalog of 200 clusters of galaxies serendipitously detected in 647 ROSAT PSPC pointings covering 158 square degrees. This is one of the largest X-ray selected cluster samples, comparable in size only to the ROSAT All-Sky…
At large redshifts, a cluster or group may be too distant for the galaxies within the cluster to be detected individually. However, the light from these ``undetected'' galaxies still modulates the surface brightness of the background sky.…
We examine the orientations of galaxies in 43 rich Abell galaxy clusters belonging to superclusters and containing at least 100 members in the considered area as a function of supercluster multiplicity. It is found that the orientation of…
Abell 2163 at $z \simeq 0.201$ is one of the most massive galaxy clusters known, very likely in a post-merging phase. Data from several observational windows suggest a complex mass structure with interacting subsystems, which makes the…
Galaxy clusters can be detected as surface brightness enhancements in smoothed optical surveys. This method does not require individual galaxies to be identifiable, and enables clusters to be detected out to surprisingly high redshifts, as…
We have conducted a redshift survey of sixteen cluster candidates from the Palomar Distant Cluster Survey (PDCS) to determine both the density of PDCS clusters and the accuracy of the estimated redshifts presented in the PDCS catalog…
Leveraging the datasets of galaxy triplets and large-scale filaments obtained from the Sloan Digital Sky Survey, we scrutinize the alignment of the three sides of the triangles formed by galaxy triplets and the normal vectors of the triplet…
We present a new cluster catalog extracted from the Sloan Digital Sky Survey Data Release 6 (SDSS DR6) using an adaptive matched filter (AMF) cluster finder. We identify 69,173 galaxy clusters in the redshift range 0.045 $\le z <$ 0.78 in…
We measure primordial alignments for the red galaxies in the sample of eight massive galaxy clusters in the southern sky from the CLASH-VLT Large Programme, at a median redshift of 0.375. We find primordial alignment with about $3\sigma$…
We investigated the influence of environment on cluster galaxies by examining the alignment of the brightest cluster galaxy (BCG) position angle with respect to the host cluster X-ray position angle. The cluster position angles were…
Based on the photometric redshift catalog of Zou H. et al. (2019), we apply a fast clustering algorithm to identify 540,432 galaxy clusters at $z\lesssim1$ in the DESI legacy imaging surveys, which cover a sky area of about 20,000 deg$^2$.…
We investigate the galactic axes orientations within 18 selected clusters, sub-structures of the Local Supercluster. For every cluster we map the parameter \Delta_{11} (Flin & God{\l}owski 1986) describing the galactic axes alignment with…
This paper has been withdrawn. I belatedly found that the alignment I saw in galaxy cluster axes was bogus. It turns out that it is due to a well-known effect called the "Fingers of God" that stretches out the redshifts of galaxies in a…
Clusters of galaxies are at the intersection of cosmic filaments and are still accreting galaxies and groups along these preferential directions, but, because of their relatively low contrast on the sky, they are difficult to detect (unless…
We have carried out a study of known clusters within the 2dF Galaxy Redshift Survey (2dFGRS) observed areas and have identified 431 Abell, 173 APM and 343 EDCC clusters. Precise redshifts, velocity dispersions and new centroids have been…
(Abstract abridged) The Abell 222 and 223 clusters are located at an average redshift z ~ 0.21 and are separated by 0.26 deg. Signatures of mergers have been previously found in these clusters, both in X-rays and at opticalwavelengths, thus…
Analyzing the halo and galaxy catalogs from the Millennium simulations at redshifts $z=0,\ 0.5,\ 1$, we determine the alignment profiles of cluster galaxies by measuring the average alignments between the major axes of the pseudo inertia…
New Chandra X-ray data and extensive optical spectroscopy, obtained with AAOmega on the 3.9 m Anglo-Australian Telescope, are used to study the complex merger taking place in the galaxy cluster Abell 2744. Combining our spectra with data…
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…