Related papers: Deconstructing A3266: A Major Merger in a Quiet Cl…
X-ray and radio observations of CIZA J2242.8+5301 suggest that it is a major cluster merger. Despite being well studied in the X-ray, and radio, little has been presented on the cluster structure and dynamics inferred from its galaxy…
Using the largest mosaic of Hubble Space Telescope images around a galaxy cluster, we map the distribution of dark matter throughout a $\sim$$6\times6$ Mpc$^2$ area centred on the cluster MS 0451-03 ($z=0.54$, $M_{200}=1.65\times10^{15}…
Radio observations of a few cool-core galaxy clusters have revealed the presence of diffuse emission on cluster scales, similar to what was found in merging clusters in the form of radio halos. These sources might suggest that a minor…
The nearest giant spiral, M31, exhibits a kinematically hot stellar disc, a global star formation episode ~2-4 Gyr ago, and conspicuous substructures in its stellar halo that are suggestive of a recent accretion event. Recent chemodynamical…
We present a detailed dynamical analysis of the rich galaxy cluster A2744, containing a powerful diffuse radio halo.Our analysis is based on redshift data for 102 galaxies, part of them recovered from unexplored spectra in the ESO archive.…
JKCS041 ($z=1.8$) is one of the most distant galaxy cluster systems known, seen when the Universe was less than 4 billion years old. Recent Sunyaev-Zeldovich (SZ) observations show a temperature decrement that is less than expected based on…
The results from Suzaku observations of the galaxy cluster Abell2256 are presented. This cluster is a prototypical and well-studied merging system, exhibiting substructures both in the X-ray surface brightness and in the radial velocity…
Collision events lead to peculiar morphologies in the intracluster gas of galaxies clusters. That seems to be the case of Abell 1644, a nearby galaxy cluster, composed of three main structures: the southern cluster that exhibits a…
We report the discovery of a new binary galaxy cluster merger, the Champagne Cluster (RM J130558.9+263048.4), using a detection method that identifies dynamically active clusters in the redMaPPer SDSS DR8 photometric galaxy cluster catalog.…
We analyze the internal structures of clusters A1689 and A2218 by applying a recent development of the method of wavelet analysis, which uses the complete information obtained from optical data, i.e. galaxy positions and redshifts. We find…
We present results from the XMM-Newton observation of the binary cluster A1750 at z = 0.086. We have performed a detailed study of the surface brightness, temperature and entropy distribution and confirm that the two main clusters of the…
We present a detailed analysis of the velocity structure of the hot intracluster medium (ICM) within the A3266 galaxy cluster, including new observations taken between June and November 2023. Firstly, morphological structures within the…
AMI observations towards CIZA J2242+5301, in comparison with observations of weak gravitational lensing and X-ray emission from the literature, are used to investigate the behaviour of non-baryonic dark matter (NBDM) and gas during the…
We present a dynamical study of the CL0023+0423 system at a redshift of z = 0.84. This system consists of two components separated in velocity space by 2900 km/s and on the plane of the sky by 0.23 h^{-1} Mpc. A kinematic analysis indicates…
Galaxy clusters, which underwent a recent ($\leq3$ Gyr) major merger, offer a harsher environment due to the global hydrodynamical disturbance and the merger-shock heated ICM. However, the aftermath of such extreme cluster interactions on…
We have identified a merging galaxy cluster with evidence of two distinct sub-clusters. The X-ray and optical data suggest that the subclusters are moving away from each other after closest approach. This cluster merger was discovered from…
Abell 2256 is a rich, nearby (z=0.0594) galaxy cluster that has significant evidence of merger activity. We present new radio and X-ray observations of this system. The low-frequency radio images trace the diffuse synchrotron emission of…
Brightest Cluster Galaxies (BCGs) might have been assembled relatively late (z<1) via mergers. By exploiting the high-resolution HST/ACS imaging, we find four BCGs (COSMOS-P 125516, 102810, 036694 and 089357) in major dry merging in 29…
Recent observations of our neighbouring galaxy M31 have revealed that its disk was shaped by widespread events. The evidence for this includes the high dispersion ($V/\sigma$ $\le$ 3) of stars older than 2 Gyr, and a global star formation…
We present a dynamical analysis of the central ~1.3 square degrees of the cluster of galaxies Abell 1367, based on 273 redshift measurements (of which 119 are news). From the analysis of the 146 confirmed cluster members we derive a…