Astrophysics (index)about

galaxy group

(group of galaxies, GrG)
(group of fifty or fewer gravitationally bound Milky-Way-sized galaxies)

A galaxy group (or group of galaxies or GrG) is a group of fifty or fewer "significant" galaxies (e.g., with the luminosity of the Milky Way or brighter) that are gravitationally bound, perhaps along with some smaller galaxies, e.g., dwarf galaxies. The Milky Way is in such a group named the Local Group. A galaxy group can be part of a galaxy cluster.

A compact group is a small group within a small volume.

(galaxy clusters,galaxies)

Referenced by:
field galaxy
galaxy cluster (CL)
Local Group (LG)
projected separation