The processes that form and shape galaxy clusters, such as infall, mergers and dynamical relaxation, tend to generate distinguishable differences between the distributions of a cluster’s giant and dwarf galaxies. Thus the dynamics of dwarf galaxies in a cluster can provide valuable insights into its dynamical history. With this in mind, we look for differences between the spatial and velocity d...

A homogeneous sample of galaxy redshifts in the core regions (R ≤ 0.5 h −1 Mpc) of 12 clusters is used to measure the frequency of substructure with different tests. In 50 % of the cases substructure is detected, a frequency which agrees well with previous studies of cluster cores. Magnitude information and rough morphological classes are also available for 80 % of the sample, allowing us to co...

Clustering is one of the popular topology management approaches that can positively influence the performance of networks. It plays significant role in VANETs. However, VANETs having highly mobile nodes lead to dynamic topology and hence, it is very difficult to construct stable clusters. More homogeneous environment produces more stable clusters. Homogeneous neighborhood for a vehicle is stron...

We report on the identification of a new cluster in the far halo of the M31 galaxy. The cluster, named Bologna 514 (B514) has an integrated magnitude M V = −8.5 ± 0.6, and a radial velocity, as estimated from two independent low-resolution spectra, V r = −456 ± 23 km/s, which fully confirms its membership to the M31 system. The observed integrated spectrum is very similar to those of classical ...

A new velocity-map imaging apparatus equipped with a laser-vaporization supersonic cluster source and a time-of-flight mass spectrometer is described for high-resolution photoelectron spectroscopy studies of size-selected cluster anions. Vibrationally cold anion clusters are produced using a laser-vaporization supersonic cluster source, size-selected by a time-of-flight mass spectrometer, and t...

We present the results of the stellar and ionized gas kinematics of 13 bright peculiar Virgo cluster galaxies. The stellar velocity field are mostly consistent with a rotation pattern, but some of them shows interesting features such as; Sshaped stellar isovelocity contours in NGC 4064, and signatures of kinematical distinct components in NGC 4429, and NGC 4698. This latter galaxy and NGC 4424 ...

We analyze the mass content of the massive strong-lensing cluster Abell 586 (z = 0.17). We use optical data (imaging and spectroscopy) obtained with the Gemini Multi-Object Spectrograph (GMOS) mounted on the 8-m Gemini-North telescope, together with publicly available X-ray data taken with the Chandra space telescope. Employing different techniques – velocity distribution of galaxies, weak grav...

We study the effect of contamination by interlopers in kinematic samples of galaxy clusters. We demonstrate that without the proper removal of interlopers the inferred parameters of the mass distribution in the cluster are strongly biased towards higher mass and lower concentration. The interlopers are removed using two procedures previously shown to work most efficiently on simulated data. One...

We study the evolution of spectral early-type galaxies in clusters, groups, and the field up to redshift 0.9 using the ESO Distant Cluster Survey (EDisCS) dataset. We measure structural parameters (circularized half-luminosity radii Re, surface brightness Ie, and velocity dispersions σ) for 154 cluster and 68 field galaxies. On average, we achieve precisions of 10% in Re, 0.1 dex in log Ie, and...

Globular clusters have long been known for presenting (at times) significant deviations from spherical symmetry. While rotation has been the main proposed explanation, other complicating factors such as their constant interaction with the strong gravitational potential of their host galaxy have made it difficult for a consensus to be reached. To address this question we have obtained high-resol...