Observational constraints on the radial mixing of stars in the galactic disk

Abstract

Several mechanisms have been proposed in the recent years that could mix stars radially in the galactic disk, which include the effect of transient spiral arms, the interaction between the bar and the spiral structure, or the tidal interaction with a satellite. I review observational evidences of this radial mixing, discussing the properties of the solar vicinity metal-rich and metal poor stars, the possible differences in the kinematics of these two groups, and briefly comment on the evolution of the radial metallicity gradient.