Centaurus A/M83 Group

The Centaurus A/M83 Group is a nearby association of galaxies in the Centaurus constellation, organized mainly into the Centaurus A and M83 subgroups.

Centaurus A Group: A nearby galaxy group centered on the giant elliptical galaxy Centaurus A. One of the association’s two principal subgroups, centered on Centaurus A.
Gravitational binding: The condition in which mutual gravity keeps a system from dispersing as its parts move. It is central to deciding whether nearby galaxies belong to a shared group.
NGC 5253: A nearby dwarf irregular galaxy undergoing intense star formation. It is a prominent nearby member associated with the M83 subgroup.
Galaxy distance measurement: The set of observational methods used to estimate distances to galaxies. Distance uncertainties affect which galaxies appear physically associated with the group.
M83 Group: A nearby galaxy group centered on the spiral galaxy Messier 83. The association’s other principal subgroup, centered on M83.
Peculiar velocity: An object's velocity relative to the smooth cosmic expansion of the universe. Galaxies’ motions beyond cosmic expansion reveal their local gravitational dynamics.
NGC 4945: A nearby edge-on spiral galaxy with an active nucleus in the Centaurus constellation. It is a major galaxy associated with the Centaurus A subgroup.
Tip of the red giant branch: A method of measuring stellar distances using the sharp luminosity limit of red giant stars. Resolved stars provide distance estimates that help map the nearby subgroups.
Centaurus A: A giant elliptical galaxy in the Centaurus constellation, notable for its active nucleus and prominent dust lane. Its galaxy anchors the Centaurus A subgroup.
Virial theorem: A relation between the average kinetic and potential energies of a stable bound system. It provides a framework for estimating the mass of gravitationally bound galaxy systems.

Linked from 1 page