2011/08/29 by Maura Brunetti, M. Brunetti, Cristina Chiappini +3 · 3 citations
Physics and Astronomy · #Angular momentum #Astronomy and Astrophysical Research #Barred spiral galaxy #Bulge #Diffusion #Galaxies: Formation, Evolution, Phenomena #Galaxy #Milky Way #Spiral galaxy #Stars #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201117566
11 pages, 9 figures, accepted for publication in Astron. Astrophys
arxiv created 2011/08/29 · openalex publication_date 2011/08/30 · arxiv updated 2015/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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.