Related papers: A substructure analysis of the A3558 cluster compl…
Context: In 2.2m MPG-ESO/WFI data we discovered several mass peaks through weak lensing, forming a possible supercluster at redshift 0.45. Through multi-colour wide-field imaging with CFHT/Megaprime and INT/WFC we identify early-type…
We present a detailed study of a close pair of clusters of galaxies, A3532 and A3530, and their environments. The \textit{Chandra} X-ray image of A3532 reveals presence of substructures on scales of $\sim$20$^{\prime\prime}$ in its core.…
Subclustering is investigated in a set of 67 rich cluster galaxy samples extracted from the ESO Nearby Abell Cluster Survey (ENACS) catalog. We apply four well-known statistical techniques to evaluate the frequency with which substructure…
Abell 85 is a nearby (z=0.055) galaxy cluster that hosts a sloshing cool core, a feature commonly reported in relaxed clusters. However, the presence of multiple past and ongoing mergers indicates that it is an active node within the Abell…
Two-dimensional high-resolution density field of galaxies of the Early Data Release of the Sloan Digital Sky Survey with a smoothing lengths 0.8 h^{-1} Mpc is applied to extract clusters of galaxies, and a low-resolution field with…
We report the discovery of a probable large scale structure composed of many galaxy clumps around the known twin clusters at z=1.26 and z=1.27 in the Lynx region. Our analysis is based on deep, panoramic, and multi-colour imaging…
We present the first results of a sub-millimeter survey of distant clusters using the new Sub-mm Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. We have mapped fields in two massive, concentrated clusters, A370 at…
Abridged] We present here new results on the space density of rich, optically-selected, clusters of galaxies at low redshift (z<0.15). These results are based on the application of the matched filter cluster-finding algorithm to 1067 deg2…
We present a weak-lensing and dynamical study of the complex cluster Abell 1758 (A1758, z = 0.278) supported by hydrodynamical simulations. This cluster is composed of two main structures, called A1758N and A1758S. The Northern structure is…
We study the clustering properties of groups and of galaxies in groups in the DEEP2 Galaxy Redshift Survey dataset at z~1. Four clustering measures are presented: 1) the group correlation function for 460 groups with estimated velocity…
We study the distribution, masses, and dynamical properties of galaxy groups in the A2142 supercluster. We analyse the global luminosity density distribution in the supercluster and divide the supercluster into the high-density core and the…
The galaxy cluster Abell 2152 is recently found to be forming a cluster-cluster system with another, more distant cluster whose core is almost perfectly aligned to that of A2152. We discuss the detectability of microlensing events where a…
A combination of $BRI$ photometry and archival Chandra X-ray data have been used to analyse the effects a minor merger has on the galaxy population of A1664. We utilise adaptive smoothing techniques in the 2D spatial distribution of cluster…
Structure formation is thought to act via hierarchical mergers and accretion of smaller systems driven by gravity with dark matter dominating the gravitational field. Combining X-ray and optical imaging and spectroscopy provides a powerful…
The use of galaxy clusters as cosmological probes relies on a detailed understanding of their properties. We aim to update the spectroscopic cluster identification of CODEX by running the spectroscopic group finder on the follow-up…
We analyse new SCUBA-2 submillimeter and archival SPIRE far-infrared imaging of a z=1.62 cluster, Cl0218.3-0510, which lies in the UKIDSS/UDS field of the SCUBA-2 Cosmology Legacy Survey. Combining these tracers of obscured star formation…
The debris from past merger events is expected and, to some extent, known to populate the stellar halo near the Sun. We aim to identify and characterise such merger debris using Gaia DR3 data supplemented by metallicity and chemical…
We use deep Hubble Space Telescope images taken with the Advanced Camera for Surveys (ACS) in the F475W and F814W filters to investigate the globular cluster systems in four edge-on Sa spiral galaxies covering a factor of 4 in luminosity.…
We have developed a method for detecting clusters in large imaging surveys, based on the detection of structures in galaxy density maps made in slices of photometric redshifts. This method was first applied to the Canada France Hawaii…
Archival XMM and ROSAT X-ray data are used to investigate the structure of the Abell 548 - Abell 3367 region. Based on previous optical studies, this is a region likely to be rich in structure though studies are in disagreement regarding…