Volume 534, October 2011
|Number of page(s)||10|
|Section||Galactic structure, stellar clusters and populations|
|Published online||05 October 2011|
Stellar diffusion in barred spiral galaxies
Geneva Observatory, University of Geneva, 1290 Sauverny, Switzerland
2 Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
Received: 24 June 2011
Accepted: 27 August 2011
We characterize empirically the radial diffusion of stars in the plane of a typical barred disk galaxy by calculating the local spatial diffusion coefficient and diffusion time-scale for bulge-disk-halo N-body self-consistent systems which initially differ in the Safronov-Toomre-QT parameter. We find different diffusion scenarios that depend on the bar strength and on the degree of instability of the disk. Marginally stable disks, with QT ~ 1, have two families of bar orbits with different values of angular momentum and energy, which determine a large diffusion in the corotation region. In hot disks, QT > 1, stellar diffusion is reduced with respect to the case of marginally stable disks. In cold models, we find that spatial diffusion is not constant in time and strongly depends on the activity of the bar, which can move stars all over the disk recurrently. We conclude that to realistically study the impact of radial migration on the chemical evolution modeling of the Milky Way the role of the bar has to be taken into account.
Key words: methods: numerical / Galaxy: bulge / galaxies: kinematics and dynamics / galaxies: spiral / galaxies: stellar content / Galaxy: disk
© ESO, 2011
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.