Compact groups of compact galaxies

The paper is a review of the most important phenomenological properties of the compact groups of compact galaxies (CCCGs) and the physical conditions of objects with well-known spectra. This paper contains a reference list of all CCCGs.     

Infrared galaxies in compact groups

IR properties of Compact Group (CG) galaxies are presented and compared with IR properties of isolated galaxies. Despite CGs displaying more E-S0s and optically bright galaxies, no differences are retrieved concerning FIR emission. The observed lack of strong FIR enhancement in the CG sample is not surprising when interpreting FIR sources in CGs as accordant redshift projections, rather than as mergers in progress. This revised version was published online in August 2006 with corrections to the Cover Date.     

Simulation of compact groups of galaxies

Self-consistent simulations of seven groups of galaxies with halos have been performed to find a constraint upon the size of missing halos around spiral galaxies. An initial galaxy, which consists of 100 superstars, has half-mass radius 41 kpc and central velocity dispersion 235 km s^–1. The simulations start from the epoch of maximum expansion. The initial conditions involve a variety of spatial distributions of galaxies, and the velocity dispersion of galaxies as would be permitted for maximum expansion. Dense groups having collapse times shorter than (2/3)H ₀ ^–1 are shown to form multiple mergers in a Hubble timeH ₀ ^–1 . From a comparison of the frequencies of cD galaxies, or multiple mergers, in observed and simulated groups, it is concluded that the effective radius of missing halos is less than 41 kpc.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

Spectral and photometric study of compact groups of compact galaxies

Results are presented from a spectral, photometric, and morphological study of two compact groups of compact galaxies (CGCG) from Shahbazian’s list. The observations were made on the 1.5-m ESO telescope and the 2.6-m telescope at the Byurakan Astrophysical Observatory (BAO) during 1999–2000. These data are compared with data for the Shahbazian compact group 4. A high spatial density of galaxies, ranging from 10000 to 100000 galaxies per Mpc³, is observed in all the groups that were studied. The discovery of a Seyfert Sy1 galaxy in the Shahbazian 355 compact group is especially noteworthy. The direct photographs of the CGCGs that were studied contain no signs of merging or tidal interactions among the members of these groups. This suggests that the galaxies in these dense systems have a common origin. __________ Translated from Astrofizika, Vol. 50, No. 3, pp. 347–353 (August 2007).