Dynamical Models for Disk Galaxies with Triaxial Halos

We construct self-consistent dynamical models for disk galaxies with triaxial, cuspy halos. We begin with an equilibrium, axisymmetric, disk-bulge-halo system and apply an artificial acceleration to the halo particles. By design, this acceleration conserves energy and thereby preserving the system’s differential energy distribution even as its phase space distribution function is altered. The halo becomes triaxial but its spherically-averaged density profile remains largely unchanged. The final system is in equilibrium, to a very good approximation, so long as the halo’s shape changes adiabatically. The disk and bulge are “live” while the halo is being deformed; they respond to the changing gravitational potential but also influence the deformation of the halo. We test the hypothesis that halo triaxiality can explain the rotation curves of low surface brightness galaxies by modelling the galaxy F568-3. Subject headings: Galaxy: kinematics and dynamics — methods: statistical — methods: N-body simulations — cosmology: dark matter