Two-Dimensional Velocity Maps of Cores of Elliptical Galaxies
Recently several elliptical galaxies were found to show decoupled core kinematics. In these objects the angular momenta of cores and outer parts are misaligned. Most of these discoveries resulted from kinematic investigations based on spectra extracted along the projected major and minor axes. It is therefore not possible to determine whether the angular momentum vectors are indeed antiparallel (as suggested e.g. in IC 1459, Franx and Illingworth, 1988) or orthogonal (as found e.g. in the case of NGC 5982, Wagner et al., 1988) or whether misalignments occur at different angles as well. In the course of mapping the velocity fields of several ‘bonna fide’ elliptical galaxies, the nuclear regions were covered in detail. The twist and distortions in the isodispersion and isovelocity maps of the central parts were studied. Evidence for kinematical misalignments by small angles was found. Such cases cannot be identified from major axis and minor axis kinematics alone and hence may occur much more often than suspected at present. Twists of the rotational velocities are expected for allmost all viewing angles in triaxial galaxies. Triaxiality alone however cannot account for distortions which do not show point-reflection symmetry.
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