Dynamical effects of the long bar in the Milky Way

We examine the dynamical effects on disk stars of a “long bar” in the Milky Way by inserting a triaxial rotating bar into an axisymmetric disk+bulge+dark halo potential and integrating 3-D orbits of 10 tracer stars over a period of 5 Gyr. The long bar has been detected via “clump giants” in the IR by López-Corredoira et al. (2007), and is estimated to have semi-major axes of (3.9×0.6×0.1) kpc and a mass of 6×10 M⊙. We find such a structure has striking effects on disk orbits. The long bar is able to move considerable inner disk material into prominent stellar streams in the solar neighborhood, apparently inconsistently with observations; furthermore it can eject inner disk material to considerable heights (several kpc) above the Galactic plane in a manner which may be inconsistent with observations. The effects of the long bar can be greatly ameliorated by reducing its density and/or making it considerably thicker vertically. These effects are under continuing study.