text: A family of two-power density models for these objects is named for Walter Dehnen.
full_question: A family of two-power density models for these objects is named for Walter Dehnen. A scaling relation forthese objects was derived by John Kormendy. The isophote twist of these objects indicates they are triaxialsystems. A scaling relation for these objects uses the diameter within which the average surface brightness is20.75 in the B-band and is the D-sub-n sigma relation. A de Vaucouleurs profile is followed both by theirnormal and extremely luminous cD types. The fundamental plane for these objects is formed by any two of theparameters effective radius, average surface brightness, and velocity dispersion. Their luminosity isproportional to their velocity dispersion according to the Faber-Jackson relation. They form the base of thetuning fork diagram. For 10 points, name this common galaxy type that's contrasted with spiral galaxies. 
first_sentence: A family of two-power density models for these objects is named for Walter Dehnen.
raw_answer: elliptical galaxies [prompt on galaxies] 