Related papers: Morphological and Luminosity Content of Poor Galax…
We use multi-fiber spectroscopy of 12 nearby, poor groups of galaxies to address whether the groups are bound systems or chance projections of galaxies along the line-of-sight, why the members of each group have not already merged to form a…
We use a new fiber spectroscopic survey of 12 nearby, poor groups of galaxies to examine the dynamics and evolution of galaxies in these common, but poorly studied, environments. Some of our conclusions are: (1) The nine groups in our…
Using the TNG100 cosmological simulation, we study the formation and evolution of compact groups of galaxies. Over a redshift range of $0 \lesssim z \lesssim 0.2$, we identify these compact groups as FoF galaxy groups with high mean surface…
We present results from an optical-IR photometric study of early-type galaxies in 19 galaxy clusters out to z=0.9. The galaxy sample is selected on the basis of morphologies determined from HST WFPC2 images, and is photometrically defined…
In order to study early type galaxies in their simplest environments, we have constructed a well-defined sample of 30 isolated galaxies. The sample contains all RC3 early-type galaxies with no other cataloged galaxy with known redshift…
We perform a comparison of the properties of galaxies in compact groups, loose groups and in the field to deepen our understanding of the physical mechanisms acting upon galaxy evolution in different environments. We select samples of…
Color gradients in early-type galaxies contain valuable clues about their formation and evolutionary histories and mechanisms. We examine color gradients in 1,700 early-type galaxies in 159 galaxy clusters spanning a redshift range of 0.05…
The colors and chemical abundances of early-type galaxies at redshifts z<0.3 are studied using a sample of nearly 9000 galaxies, selected from the Sloan Digital Sky Survey using morphological and spectral criteria. In this sample, redder…
The slow evolution of the M/L ratios, colors, and line strengths of cluster early-type galaxies to z=1 suggests that their stars were formed at very high redshift. At the same time, morphological studies of distant clusters indicate…
Isolated galaxies are important since they probe the lowest density regimes inhabited by galaxies. We define a sample of 36 nearby isolated early-type galaxies for further study. Our isolation criteria require them to have no…
(Abridged) We present new optical and near-infrared imaging for a sample of 98 spectroscopically-selected galaxy groups at 0.25<z<0.55. We measure accurate colours for group members and the surrounding field population, statistically…
Many of the early-type galaxies observed so far at z>1 turned out to have smaller radii with respect to that of a typical present-day early-type galaxy with comparable mass. This has generated the conviction that in the past early-type…
We study morphology and luminosity segregation of galaxies in loose groups. We analyze the two catalogs of groups which have been identified in the Nearby Optical Galaxy (NOG) sample, by means of hierarchical and percolation…
We compare properties of galaxies in loose groups with those in field environment by analyzing the Nearby Optical Galaxy (NOG) catalog of galaxy systems. We consider as group galaxies, objects belonging to systems with at least five members…
We use catalogues of superclusters of galaxies from the 2dF Galaxy Redshift Survey to study the properties of galaxies in superclusters. We compare the properties of galaxies in high and low density regions of rich superclusters, in poor…
We present a pedagogical review on the formation and evolution of galaxies in groups, utilizing observational information from the Local Group to galaxies at z~6. The majority of galaxies in the nearby universe are found in groups, and…
We investigate the galaxy populations in seven X-ray selected, intermediate-redshift groups (0.2<z<0.6). Overall, the galaxy populations in these systems are similar to those in clusters at the same redshift; they have large fractions of…
The evolution of galaxies in groups may have important implications for the evolution of the star formation history of the universe, since many processes which operate in groups may suppress star formation and the fraction of galaxies in…
We analyse a sample of about 2000 galaxies in 40 regular clusters, to look for evidence of segregation with respect to galaxy luminosities and morphological types. We find evidence of luminosity segregation for galaxies brighter than $M_R <…
Compact groups of galaxies have posed a number of challenging questions. Intensive observational and theoretical studies are now providing answers to many of these, and at the same time, are revealing unexpected new clues about the nature…