2012ApJ...759...64L

I have combined the Emsellem et al. ATLAS^3D rotation measures of a large sample of early-type galaxies with Hubble Space Telescope based classifications of their central structure to characterize the rotation velocities of galaxies with cores. "Core galaxies" rotate slowly, while "power-law galaxies" (galaxies that lack cores) rotate rapidly, confirming the analysis of Faber et al. Significantly, the amplitude of rotation sharply discriminates between the two types in the -19 > M_V> -22 domain over which the two types coexist. The slow rotation in the small set of core galaxies with M_V> -20, in particular, brings them into concordance with the more massive core galaxies. The ATLAS^3D "fast-rotating" and "slow-rotating" early-type galaxies are essentially the same as power-law and core galaxies, respectively, or the Kormendy & Bender two families of elliptical galaxies based on rotation, isophote shape, and central structure. The ATLAS^3D fast rotators do include roughly half of the core galaxies, but their rotation amplitudes are always at the lower boundary of that subset. Essentially, all core galaxies have ATLAS^3D rotation amplitudes λ_Re_/2 ≤ 0.25, while all galaxies with λ_Re_/2 > 0.25 and figure eccentricity >0.2 lack cores. Both figure rotation and the central structure of early-type galaxies should be used together to separate systems that appear to have formed from "wet" versus "dry" mergers.