Dark matter in elliptical galaxies - the case of NGC 3311

Tom Richtler

Universidad de Concepción

The question whether elliptical galaxies fall onto the same baryonic Tully-Fisher-relation as spiral galaxies, obviously is critical for the universal character of the phenomenology among galaxies. Because the uncertainty of individual mass determinations is considerable, satifactory answers are only expected from appropriate samples of nearby galaxies. The present literature on elliptical galaxy masses from dynamical tracers does not give a clear-cut answer: some galaxies are "MONDian", others apparently not. The largest deviations from the baryonic TF relation are found for central galaxes in clusters. I report on our work on NGC3311, the central galaxy in the Hydra I cluster. I argue that its massive cored dark halo found previously probably is a manifestion of the inhomogeneity of infalling tracer populations. Whether galaxy clusters are MONDian or not, still remains to be seen.