Moving groups and the non-axisymmetries of the Galactic disk

Séminaire IPAG de Benoit Famaey (Obs. de Strasbourg), jeudi 10 janvier 2013 à 11h00, IPAG seminar room

We show that classical moving groups in the velocity field of the solar neighbourhood (e.g., the Hercules, Pleiades, Hyades and Sirius moving groups) are not made of co-eval stars. This favors a dynamical origin for these phase-space structures rather than the dissolution of open clusters. We show how such phase-space structures are indeed triggered by the non-axisymmetric features of the Galactic disk, namely the bar and spiral arms, and how radial migrations of stars through the Galactic disk can also ensue from this. This radial mixing can bring high-metallicity stars from the inner Galaxy to the solar neighbourhood, and we will discuss the possibility that the correlation between the presence of giant planets and the metallicity of their host stars could be a consequence of this Galactic mixing process.