出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Hickson Compact Groups (HCGs) are excellent laboratories for the study of the influence of the
environment on galaxies. We used dwarf galaxies as tracers and identified them in the outer
regions of HCGs with the intention to investigate if the groups are physically bound systems or
chance configurations of individual galaxies. In order to establish the dwarf galaxy content of such
groups, we observed a sample of five HCGs (16, 19, 30, 31, 42) with the WFI (0
54 0
57) at
the ESO/MPIA 2.2mtelescope at La Silla and found more than 2000 new dwarf galaxy candidates
in each group. In order to determine the group membership of dwarf elliptical (dE) galaxies we
used the red sequence of the Color Magnitude Diagram and additionally morphology, radial light
profile, and the surface brightness of the candidate galaxies.
From this analysis it is possible to draw the conclusion that the CGs of our sample are not chance
configurations but physically bound systems where dE galaxies have evolved due to the influence
of their surroundings. The density distribution of these galaxies decreases from the center to the
boundaries of our mosaic data. In all of our HCGs the dwarf galaxy members extend far beyond
the density centers of catalogued CGs. Using velocity information of a subsample we calculated
the radius of the zero–velocity–surface which is in the order of 2 Mpc indicating sizes similar to
galaxy clusters. The determined Luminosity Function (LF) of HCGs matches with the predicted
LF of Cold Dark Matter models of dense environments.
