there was mass stripping from a galaxy and if the system had time to relax, then, the potential should be axisymmetric and both sides of the rotation curve should fall. We observe no such rotation curves among compact group galaxies. However, if the interaction is very recent and the system did not have time to relax, the potential could be non-axisymmetric (triaxial) and the resulting rotation curve could have the observed shape. Another possibility is that the halo could be just shaken (not stripped), in which case we would also expect to observe non-axisymmetric rotation curves such as those we observe among compact group galaxies. More N-body simulations are necessary to further clarify these issues.

The prospects for the future are (1) to use near-infrared imaging to check this result, (2) combine rotation curves with surface brightness profiles to model what role the dark matter plays in the mass distribution, specially to detect galaxies that are dominated by dark matter in their central parts, if there are any and (3) to use other more external (to the group) test-particles to test the halo properties at larger radii (e.g. planetary nebula, globular clusters and/or dwarf galaxies). Finally, a detailed comparison of 