Dwarf elliptical galaxy

The surface brightness profiles of ordinary elliptical galaxies was formerly approximated using de Vaucouleur's model, while dEs were approximated with an exponentially declining surface brightness profile.

Within the currently favoured cosmological Lambda-CDM model, small objects (consisting of dark matter and gas) were the first to form.

Because of their mutual gravitational attraction, some of these will coalesce and merge, forming more massive objects.

The process of coalescence could lead to the present-day galaxies, and has been called "hierarchical merging".

Evidence for this latter hypothesis has been claimed due to stellar disks and weak spiral arms seen in some dEs.