Related papers: Compact groups from the Millennium Simulations: I.…
We study a sample of 43 early-type galaxies, selected from the SDSS because they appeared to have velocity dispersion > 350 km/s. High-resolution photometry in the SDSS i passband using HRC-ACS on board the HST shows that just less than…
[Abridged] The environment where galaxies are found heavily influences their evolution. Close groupings, like the cores of galaxy clusters or compact groups, evolve in ways far more dramatic than their isolated counterparts. We have…
We investigate the structural, kinematical, and chemical properties of globular cluster systems (GCSs) in galaxies of different Hubble types in a self-consistent manner based on high-resolution cosmological N-body simulations combined with…
Using over 3000 compact groups (CGs) of galaxies extracted from mock catalogues built from semi-analytical models of galaxy formation (SAMs), we study whether the CG assembly channel affects the z=0 properties of galaxies and their…
The sample of known star clusters, the fundamental building blocks of galaxies, in the Milky Way is still extremely incomplete for objects beyond a distance of 1-2kpc. Many of the more distant and young clusters are compact and hidden…
We have recently extracted a catalog of compact groups of galaxies (CGs) from the Las Campanas Redshift Survey. This catalog of Las Campanas Compact Groups (LCCGs) contains 76 CGs with a median redshift of z_med = 0.08. The physical…
We explore galaxy properties and their link with environment and clustering using a population of ~1000 galaxies formed in a high resolution hydrodynamic simulation of the Lambda CDM cosmology. At the redshift we concentrate on, z=1, the…
We investigate the morphology and structural properties of 246 massive compact quiescent galaxies (MCGs; $\log M_{\star} \sim 10$-$11$, $\sigma_{\mathrm{e}} \sim 150$-$350\,$km\,s$^{-1}$, $R_{\mathrm{e}} \sim 0.7$-$2.5\,$kpc) at $z \sim 0$,…
The nature of Compact Groups (CGs) is investigated by comparing the luminosities and morphologies of CG galaxies, CG Neighbours and Isolated galaxies. CGs turn out to include more early type galaxies than Isolated galaxies and fewer…
We study the clustering properties of groups and of galaxies in groups in the DEEP2 Galaxy Redshift Survey dataset at z~1. Four clustering measures are presented: 1) the group correlation function for 460 groups with estimated velocity…
We present H$_\alpha$ photometry for a sample of 95 galaxies in Hickson Compact Groups obtained from observations of 31 groups. The Catalogue lists isophotal and adaptive aperture (Kron aperture) flux measurements for about 75% of the…
Compact groups are associations of a few galaxies in which the environment plays an important role in galaxy evolution. The low group velocity dispersion favors tidal interactions and mergers, which may bring stars from galaxies to the…
We have systematically analyzed a sample of 13 new and archival ROSAT PSPC observations of compact groups of galaxies: 12 Hickson Compact Groups plus the NCG 2300 group. We find that approximately two-thirds of the groups have extended…
We present a weak lensing analysis of a sample of SDSS Compact Groups (CGs). Using the measured radial density contrast profile, we derive the average masses under the assumption of spherical symmetry, obtaining a velocity dispersion for…
Applying an automatic neighbour search algorithm to the 3D UZC galaxy catalogue (Falco 1999) we have identified 291 compact groups (CGs) with redshifts between 1000 and 10000 km/s. The sample is analysed to investigate whether Triplets…
We have conducted an HI 21 cm emission-line survey using the Parkes 20cm multibeam instrument and the Australia Telescope Compact Array (ATCA) of six loose groups of galaxies chosen to be analogs to the Local Group. The goal of this survey…
Redshift Survey Compact Groups (RSCGs) are tight knots of N >= 3 galaxies selected from the CfA2+SSRS2 redshift survey. The selection is based on physical extent and association in redshift space alone. We measured 300 new redshifts of…
Compact groups have high galaxy densities and low velocity dispersions, and their group members have experienced numerous and frequent interactions during their lifetimes. They provide a unique environment to study the evolution of…
Compact galaxy groups are at the extremes of the group environment, with high number densities and low velocity dispersions that likely affect member galaxy evolution. To explore the impact of this environment in detail, we examine the…
We report on analyses of cluster samples obtained from the Hubble Volume Simulations. These simulations, an $\Omega=1$ model named $\tau$CDM and a flat low $\Omega$ model with a cosmological constant ($\Lambda$CDM), comprise the largest…