Origin of the Moving Groups and Their Contribution to the Determination of the Large-scale Galactic Potential

Abstract

We evaluate the hypothesis that relates the formation of moving groups to the resonances of the non-axisymmetric component of the Galactic potential (spiral arms and central bar). We apply multiscale techniques to an extensive sample of more than 24,000 stars of the solar neighborhood to characterize the kinematic structures in the U–V – age – [Fe/H] space. The observational data is compared with the distribution in the kinematic plane obtained through the computation of test particle orbits under analytic models for the potential. Results from two different models for the spiral structure and/or the Galactic bar are presented here. We show that the simulations near the position of the ILR − 1:4 of the spiral structure and the OLR 1:2 of the Galactic bar are able to reproduce kinematic structures similar to the observed ones. We discuss the fundamental role of the age and metallicity distributions in the confirmation of the hypothesis.