1 research outputs found
Local Group(s)
The properties of the galaxies of the Local Group are reviewed, followed by a
brief discussion of nearby groups. The galaxy groups in our vicinity - the M81
group, the Cen A group, and the IC 342/Maffei group - are in many respects
Local Group analogs: Their luminosity functions, galaxy content, fractional
galaxy type distribution, crossing times, masses, and zero-velocity surface
radii are similar to those of the Local Group. Also, the nearby groups usually
consist of two subgroups, some of which approach each other and may ultimately
merge to form a fossil group. These poor groups contrast with the less evolved,
loose and extended galaxy ``clouds'' such as the Scl group and the CVn I cloud.
These are characterized by long crossing times, are dominated by gas-rich,
late-type galaxies, and lack gas-deficient, low luminosity early-type dwarfs.
These clouds may be groups still in formation. The local Hubble flow derived
from the clouds and groups is very cold.Comment: 17 pages, no figures. Invited review to appear in the proceedings of
the ESO workshop "Groups of Galaxies in the Nearby Universe", Santiago, Dec
5-9, 2005. Eds. I. Saviane, V. Ivanov, & J. Borissova (Springer Verlag