For 10 points, name these entities that are gravitationally bound systems of dark matter, stars, and dust.
The CfA2 Great Wall is a filament made of these entities. Seyfert ones exhibit Doppler broadening of their spectra, indicating the presence of an active nucleus. The distribution of heavy elements is one factor in determining the "habitable zone" in these entities. Velocity dispersion is related to their luminosity in the Tully-Fisher relation, but this relation only holds when the object is on one of the tongs of Hubble's Tuning Fork, which categorizes these objects into elliptical, barred, and spiral. For 10 points, name these entities that are gravitationally bound systems of dark matter, stars, and dust.
The CfA2 Great Wall is a filament made of these entities. Seyfert ones exhibit Doppler broadening of their spectra, indicating the presence of an active nucleus.
Galaxy [accept Galaxies]