Related papers: Mid-Infrared Evidence for Accelerated Evolution in…
Recent observations have highlighted a significant population of faint but large (r_eff>1.5 kpc) galaxies in the Coma cluster. The origin of these Ultra Diffuse Galaxies (UDGs) remains puzzling, as the interpretation of the observational…
Deep $B$ and $R$ images of three Hickson Compact Groups, HCG 79, HCG 88 and HCG 95, were analyzed using a new wavelet technic to measure possible intra-group diffuse light present in these systems. The method used, OV\_WAV, is a wavelet…
We employ spectroscopic and photometric data from SDSS DR7, in a 500 sq degree region, to understand the evolution of dwarf (~M*+2<M_z<M*+4) galaxies in the Coma supercluster (z=0.023). We show that in the Coma supercluster, the red dwarfs…
Massive Ultracompact Galaxies (MUGs) are common at z=2-3, but very rare in the nearby Universe. Simulations predict that the few surviving MUGs should reside in galaxy clusters, whose large relative velocities prevent them from merging,…
We present new Fabry-Perot observations for a sample of 42 galaxies located in twelve compact groups of galaxies: HCG 1, HCG 14, HCG 25, HCG 44, HCG 53, HCG 57, HCG 61, HCG 69, HCG 93, VV 304, LGG 455 and Arp 314. From the 42 observed…
The nature of compact groups (CGs) of galaxies, apparently so dense that the galaxies often overlap, is still a subject of debate: Are CGs roughly as dense in 3D as they appear in projection? Or are they caused by chance alignments of…
Compact groups of galaxies provide a unique environment to study the evolution of galaxies amid frequent gravitational encounters. These nearby groups have conditions similar to those in the earlier universe when galaxies were assembled and…
We present the analysis of Halpha3, an Halpha imaging survey of galaxies selected from the HI ALFALFA Survey in the Coma Supercluster. By using the Halpha line as a tracer of the "instantaneous" star formation, complemented with optical…
Pre-processing within small groups has been proposed to explain several of the properties of galaxies inhabiting rich clusters. The aim of the present work is to see whether pre-processing is acting in the nearby universe, where the…
Context. In spite of the numerous studies of low-luminosity galaxies in different environments, there is still no consensus about their formation scenario. In particular, a large number of galaxies displaying extremely low-surface…
We present here results from a deep spectroscopic survey of the Coma cluster of galaxies (29 galaxies between 18.98<m_R<21.5). Only 1 of these galaxies is within Coma compared to an expected 6.7 galaxies computed from nearby control fields.…
The stability and longevity of globular clusters (GCs) make them effective tracers of the dynamical histories of galaxies in cluster environments. We construct a catalog of 23,351 GC candidates in the Coma cluster using imaging from the…
We present the results of the spectral classification of the 82 brightest galaxies in a sample of 17 compact groups. We verify that the AGNs are preferentially located in the most early-type and luminous galaxies of the groups, as is…
Multi-wavelength observations of Hickson's Compact Groups (HCGs) have shown that many of these groups are physical bound structures and are in different stage of evolution, from spiral-dominated systems to almost merged objects. Very few…
Central Galaxies (CGs) in massive halos live in unique environments with formation histories closely linked to that of the host halo. In local clusters they have larger sizes ($R_e$) and lower velocity dispersions (sigma) at fixed stellar…
Aims: Following the study already presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18 $\leq$ z $\leq$ 0.25, imaged in the central…
A new sample of 4299 galaxies with X-ray emission was obtained in this work by cross-correlating 2XMM catalog of X-ray sources with HyperLeda database of galaxies. We analyzed distributions of optical and X-ray fluxes, redshifts and X-ray…
We use 16 micron, Spitzer-IRS, blue peakup photometry of 50 early-type galaxies in the Coma cluster to define the mid-infrared colour-magnitude relation. We compare with recent simple stellar population models that include the mid-infrared…
The fraction of star-forming galaxies in rich clusters of galaxies increases rapidly with the redshift. This is interpreted as the result of a rapid evolution of cluster galaxies, though its mechanism is not yet clear. One hypothesis is…
A dataset of 23,351 globular clusters (GCs) and ultra-compact dwarfs (UCDs) in the Coma cluster of galaxies was built using Hubble Space Telescope Advanced Camera for Surveys data. Based on the standard magnitude cut of $M_V \leq -11$, a…