Radial migration in a stellar galactic disc with thick components
Max Planck Institut für Astrophysik,
Garching bei München,
2 Observatoire de Paris, GEPI, 5 place Jules Janssen, 92190 Meudon, France
3 LERMA, Observatoire de Paris, Collège de France, CNRS, PSL Université, UPMC, Sorbonne Université, Paris, France
Accepted: 6 March 2018
We study how radial migration affects the stars of a galaxy with a thin stellar disc and thicker stellar components. The simulated galaxy has a strong bar and lasting spiral arms. We find that the amplitude of the churning (change in angular momentum) is similar for thin and thick components, and of limited amplitude, and that stars of all components can be trapped at the corotation of the bar. With the exception of those stars trapped at the corotation, we find that stars far from their initial guiding radius are more likely to be so due to blurring rather than churning effects. We compare the simulation to orbits integration with a fixed gravitational potential rotating at a constant speed. In the latter case, stars trapped at corotation are churned periodically outside and inside the corotation radius, with a zero net average. However, as the bar speed of the simulated galaxy decreases and its corotation radius increases, stars trapped at corotation for several Gyrs can be churned on average outwards. In this work we have studied the location of extreme migrators (stars experimenting the largest churning) and find that extreme migrators come from regions on the leading side of the effective potential local maxima.
Key words: galaxies: evolution / galaxies: structure / galaxies: stellar content
© ESO 2018
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.