Families of galaxies in the e-Re plane

Using a complete sample of Virgo cluster galaxies and a larger set of heterogeneous literature data, we show that ellipticals, early-type dwarfs, and bulges of S0s and of spirals form two distinct families in the plane of the effective parameters, R e and μ e . The «ordinary» family is composed of all galaxies fainter than M B ≃−19.3. Their effective parameters range over a wide interval for the same total luminosity: R e varies by at least ∼0.7 dex and μ e by 3.5 mag. Moreover, the interval spanned by R e is the same at any luminosity (down to M B ≃−12.0), with a sharp upper boundary at R e ≃3 kpc.