Interaction between a galactic disk and a live dark halo with an anisotropic velocity distribution

¹ Astronomisches Rechen-Institut, Mönchhofstrasse 12–14, 69120 Heidelberg, Germany e-mail: fuchs@ari.uni-heidelberg.de
² Observatoire de Marseille, 2 Place Le Verrier, 13248 Marseille Cedex 04, France

Received: 17 February 2005
Accepted: 21 September 2005

Abstract

We have extended previous analytical studies of the interaction of dark halos with galactic disks by introducing for the halo particles anisotropic distribution functions in phase space. For this purpose we have employed the shearing sheet model of a patch of a galactic disk embedded in a homogeneous halo. We find that velocity anisotropy increases considerably the maximum growth factor of perturbations in the disk.