2013/01/11 by P. Di Matteo, M. Haywood, F. Combes +2 · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Azimuth #Bar (unit) #Distribution (mathematics) #Electrical and Electromagnetic Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Metallicity #Milky Way #Spiral galaxy #Stars #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201220539
8 pages, 10 figures, accepted for publication on Astronomy and Astrophysics
arxiv created 2013/01/11 · openalex publication_date 2013/02/13 · arxiv updated 2015/06/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
By means of N-body simulations, we show that radial migration in galaxy disks, which is induced by bar and spiral arms, leads to significant azimuthal variations in the metallicity distribution of old stars at a given distance from the galaxy center. Metals do not show an axisymmetric distribution during phases of strong migration. Azimuthal variations are visible during the whole strong bar phase, and they tend to disappear as the effect of radial migration diminishes, together with a reduction in the bar strength. These results suggest that the presence of inhomogeneities in the metallicity distribution of old stars in a galaxy disk can be a probe of ongoing strong migration. Such signatures may be detected in the Milky Way by Gaia (and complementary spectroscopic data), as well as in external galaxies, by IFU surveys like CALIFA and ATLAS3D. Mixing – defined as the tendency toward a homogeneous, azimuthally symmetric, stellar distribution in the disk – and migration turns out to be two distinct processes, the effects of mixing starting to be visible when strong migration is over.