Key points are not available for this paper at this time.
Rotation curves and velocity dispersion profiles have been determined for the major and the minor axes of 22 elliptical galaxies. The uncertainty in the mean rotational velocity is typically only 5 km s^-1^ for either axis. Rotation () >= 20 km s^-1^) was detected in all but one galaxy (NGC 5846), even though the sample was biased toward round ellipticals. Minor axis rotation larger than the major axis rotation was measured in two galaxies, NGC 4406 and NGC 7507. While the sample of such galaxies is still small (now three in total), it appears plausible that ~ 10% of ellipticals may show large minor axis velocities relative to those on the major axis. Two more ellipticals, NGC 1549 and NGC 7145, show vₘinor_ ~ vₘajor_. In total six galaxies, or 27% of the sample, show significant minor axis rotation. A simple model is used to derive a rotational axis from the observed minor and major axis velocities to a typical accuracy of 6ᵈeg^. The rotational and photometric minor axes align to better than 10ᵈeg^ for 60% of the sample. This implies that the direction of the angular momentum is related to the orientation of the figure of the galaxy. This is surprising, since ellipticals are not supported by rotation, and considerable freedom in the direction of the angular momentum is allowed if galaxies are triaxial and have insignificant figure rotation. This suggests that figure rotation could play an important role in elliptical galaxies, or that these galaxies are near to oblate, and/or that events during the formation of elliptical galaxies conspire to orient the figure such that the angular momentum vector aligns approximately with the shortest of the principal axes. The galaxies with large photometric twists generally show significant kinematic misalignment. In addition, the centers of these galaxies are better aligned photometrically with their kinematic axes than are the outer parts. At least two galaxies have rapidly rotating, kinematically skew components in their cores. IC 1459 has a kinematically distinct core with its angular momentum opposite to the angular momentum of the outer parts, and NGC 4406 (a minor-axis rotator) has a core with its angular momentum perpendicular to that of the outer parts. The outer part of the latter galaxy may well rotate around the long axis. An additional four galaxies show weaker effects that need confirmation. The minor axis rotation and the misaligned cores support the view that ellipticals as a class are triaxial.
Franx et al. (Fri,) studied this question.