Benois Famaey, CNRS/Strasbourg
Current Galactic dynamical models still often rely on the zeroth order assumptions of a smooth time-independent and axisymmetric gravitational potential. First order perturbed models are those trying to isolate the effects of one main perturber, such as the bar or the spiral arms. In this talk, we show how a single internal perturber can generate horizontal and vertical bulk motions, in the form of “galactoseismic” oscillation modes. We also show that non-linear couplings can be present when multiple perturbers are taken into account simultaneously. We argue that, in future dynamical modeling of the Galaxy, one should simultaneously fit all these effects without too strong priors on the shape of the potential of the fiducial axisymmetric background. Such modeling should allow us to put constraints on the nature and amplitude of non-axisymmetries in the Milky Way with future and ongoing large surveys.