Related papers: Are dumbbell brightest cluster members signposts t…
Photographic F band photometry of a sample of 36 Abell clusters has been used to study the relation between the magnitude $M_1$ of the brightest cluster member and the Schechter function parameter $M^*$. Clusters appear segregated in the…
Diffuse radio emission in galaxy clusters, and their connection with cluster mergers, are still debated. We seek to explore the internal dynamics of the radio halo cluster Abell 545. This cluster is also peculiar for hosting in its center a…
A large fraction of the stellar mass in galaxy clusters is thought to be contained in the diffuse low surface brightness intracluster light (ICL). Being bound to the gravitational potential of the cluster rather than any individual galaxy,…
We study the possible rotation of cluster galaxies, developing, testing and applying a novel algorithm which identifies rotation, if such does exist, as well as its rotational centre, its axis orientation, rotational velocity amplitude and,…
I discuss and review recent studies of the signatures of activity in brightest cluster galaxies. Mid-IR spectra appear to show indications of star formation in a sample of 9 BCGs from de Messieres et al. (2009). Other processes like cosmic…
Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. The basic properties of cluster mergers and their…
We present here our results on a complete sample of Brightest Cluster Galaxies (BCGs) in nearby Abell Clusters (distance class <3). Combined with data from the literature, we provide parsec scale information for 34 BCGs. We found that also…
We have examined the orientations of brightest cluster galaxies (BCGs) in poor MKW and AWM clusters and find that, like their counterparts in richer Abell clusters, poor cluster BCGs exhibit a strong propensity to be aligned with the…
We compile a sample of spectroscopically- and photometrically-selected cluster galaxies from four high-redshift galaxy clusters ($1.59 < z < 1.71$) from the Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS), and a comparison…
Cluster of galaxies are the largest concentrations of visible mass in the Universe and therefore a fundamental topic of cosmology and astrophysics. Recent radio, EUV, and X-ray observations suggest that clusters contain large populations of…
We present clustering measurements for samples of galaxies selected by morphological type and luminosity from the recently completed Stromlo-APM Redshift Survey. Early type galaxies are clustered more strongly by a factor 3.5--5.5, than…
The analysis of the presence of substructures in 16 well-sampled clusters of galaxies suggests a stimulating hypothesis: Clusters could be classified as unimodal or bimodal, on the basis of to the sub-clump distribution in the {\em 3-D}…
We identify close companions of Brightest Cluster Galaxies (BCGs) for the purpose of quantifying the rate at which these galaxies grow via mergers. By exploiting deep photometric data from the CFHTLS, we probe the number of companions per…
The dependence of the luminosity function of cluster galaxies on the evolutionary state of the parent cluster is still an open issue, in particular as concern the formation/evolution of the brightest cluster galaxies. We plan to study the…
We report the detection of a pair of massive quiescent galaxies likely in the process of merging at the center of the spectroscopically confirmed, extremely massive protocluster BOSS1244 at $z=2.24\pm0.02$. These galaxies, BOSS1244-QG1 and…
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…
Observations of early-type dwarf galaxies in clusters often show that cluster dwarf members have significantly higher velocities and less symmetric distributions than cluster giant ellipticals, suggesting that these dwarfs are recently…
We present new VLBI observations at 5 GHz of a complete sample of Brightest Cluster Galaxies (BCGs) in nearby Abell Clusters (distance class <3). Combined with data from the literature, this provides parsec-scale information for 34 BCGs.…
The high-density environment of galaxy clusters is ripe for collisional encounters of galaxies. While the large velocity dispersion of clusters was originally thought to preclude slow encounters, the infall of smaller groups into the…
A brief overview of the properties of massive star clusters in early-type galaxies is given. All ellipticals (with only one known exception) host massive star clusters in the form of globular clusters, suggesting that their formation is…