Related papers: Compact groups from the Millennium Simulations: I.…
In order to explore the statistical properties of galaxy morphological types in compact groups (CGs), we construct a random group sample which has the same distributions of redshift and number of member galaxies as those of the CG sample.…
In this paper we present an objectively defined catalog of 459 small, high density groups of galaxies out to z~0.2 in a region of 6260 square degrees in the northern sky derived from the Digitized Second Palomar Observatory Sky Survey. Our…
Compact group galaxies often appear unaffected by their unusually dense environment. Closer examination can, however, reveal the subtle, cumulative effects of multiple galaxy interactions. Hickson Compact Group (HCG) 59 is an excellent…
Upcoming large galaxy surveys will subject the standard cosmological model, $\Lambda$CDM, to new precision tests. These can be tightened considerably if theoretical models of galaxy formation are available that can predict galaxy clustering…
We use an updated version of the halo-based galaxy group catalog of Yang et al., and take the surface brightness of the galaxy group ($\mu_{\rm lim}$) based on projected positions and luminosities of galaxy members as a compactness proxy to…
Simulations of nearby (0.015 < z < 0.025) SDSS galaxies have been used to reproduce as accurately as possible the appearance that they would have on COSMOS ACS images if they had been observed at z ~ 0.7 and z ~ 1.2. By adding the SDSS…
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 an optical group catalog between 0.1 < z < 1 based on 16,500 high-quality spectroscopic redshifts in the completed zCOSMOS-bright survey. The catalog published herein contains 1498 groups in total and 192 groups with more than…
Two algorithms for the identification of galaxy groups from redshift surveys are tested by application to simulated data derived from N-body simulation. The accuracy of the membership assignments by these algorithms is studied in a…
We study the formation and the evolution of galaxy groups in a critical universe, showing the importance of secondary infall for their dynamical evolution. Merging is only slightly accelerated if galaxies have massive halos, because the…
We report the results of a multi-waveband analysis of the masses and luminosities of $\sim$600 galaxy groups and clusters identified in the maxBCG catalogue. These data are intended to form the basis of future work on the formation of the…
We use various samples of compact groups (CGs) to examine the types of association CGs have with rich and poor clusters of galaxies at low (z~0.04) and intermediate (z~0.1) redshifts. We find that ~10-20 % of CGs are associated with rich…
We present a global study of HI spectral line mapping for 16 Hickson Compact Groups (HCGs) combining new and unpublished VLA data, plus the analysis of the HI content of individual galaxies. Sixty percent of the groups show morphological…
Abridged] We present here new results on the space density of rich, optically-selected, clusters of galaxies at low redshift (z<0.15). These results are based on the application of the matched filter cluster-finding algorithm to 1067 deg2…
The HST ACS Coma Cluster Treasury Survey is a deep two passband imaging survey of the nearest very rich cluster of galaxies, covering a range of galaxy density environments. The imaging is complemented by a recent wide field redshift survey…
We present an all-sky catalogue of 395 nearby galaxy groups revealed in the Local Supercluster and its surroundings. The groups and their associations are identified among 10914 galaxies at |b|>15deg with radial velocities VLG<3500 km/s.…
Isolated compact groups of galaxies (CGs) present a range of dynamical states, group velocity dispersions, and galaxy morphologies with which to study galaxy evolution, particularly the properties of gas both within the galaxies and in the…
From the poor cluster catalog of White et al. (1996), we define a sample of 71 optically-selected poor galaxy clusters. The surface-density enhance- ment we require for our clusters falls between that of the loose associations of Turner and…
From a volume limited sample of 45,542 galaxies and 6,000 groups with $z \leq 0.213$ we use an adapted minimal spanning tree algorithm to identify and classify large scale structures within the Galaxy and Mass Assembly (GAMA) survey. Using…
We compare the use of galaxy asymmetry and pair proximity for measuring galaxy merger fractions and rates for a volume limited sample of 3184 galaxies with -21 < M(B) -5 log h < -18 mag. and 0.010 < z < 0.123 drawn from the Millennium…