1) Speaker: S.A. Khoperskov (INASAN)
Title: “The Milky Way chemo-kinematics: spiral arms, bar resonances, ridges and moving groups”
Abstract: By using superb Gaia Data Release 2 measurements of positions and velocities of stars complemented by chemical abundances delivered by APOGEE DR16, LAMOST DR5 and Galah DR2 spectroscopic surveys, we explore chemo-dynamical properties of the Milky Way spiral arms and constrain the location of the main resonances of the bar. Combining the data analysis with high-resolution N-body simulations we deliver a consistent explanation of the large scale patterns observed in the Galactic plane with the origin of moving groups in the local kinematic space. We provide the match between the kinematical arches in the vR-vphi plane, diagonal vphi-R ridges and the known spiral arms of the Milky Way. Both the Outer Lindblad and corotation resonances are imprinted in the VR-vphi plane, as a part of the Hercules and the Sirius streams, respectively, which is further evidence of slowly rotating long bar. On large galactic scales, the crossmatch of the Gaia DR 2 with the spectroscopic data allows us to discover the abundance variations across the spiral arms of the Milky Way disk. We discuss these results in the context of the spiral arms induced kinematical fractionality and ongoing radial migration in the Milky Way disk.
The seminar will be held online.