Type-cD galaxy

Characterized by a large halo of stars,[4] they can be found near the centres of some rich galaxy clusters.

[13] Massive galaxies such as supergiant elliptical galaxies are important to understanding the evolution of the Universe, because they, along with other large-early type galaxies, account for half of the Universe's stellar mass, contribute a lot to its chemical enrichment and provide clues to the star formation history of the Universe.

[19] This "cannibalistic" mode of growth leads to the large diameter and luminosity of the cDs.

This over-density follows behind the larger galaxy and exerts a constant gravitational force on it, causing it to slow down.

As it loses kinetic energy, the large galaxy gradually spirals toward the centre of the cluster.

[24] A giant or supergiant diffuse or elliptical galaxy will result from this accumulation.