Rotation (upper) and dispersion (lower) profiles NGC 3593. Open circles are measurements for stars, filled circles are for gas (from H
). These two components rotate in opposite directions. (from Bertola et al 1996 o-link)
The double stellar disks in NGC 4550. Light profile (upper); dispersion (second); and rotation (third) of the two disks. Each disk has the same scale length, and is relatively cold (low-ish dispersion). As in NGC 3593 these two disks rotate in opposite directions. (from Rix et al 1992 o-link)