Abundance anomalies in red giants with possible extragalactic origins unveiled by APOGEE-2
Abstract
By performing an orbital analysis within a Galactic model including a bar, we found that it is plausible that the newly discovered stars that show enhanced Al and N accompanied by Mg underabundances may have formed in the outer halo, or were brought in by satellites field possibly accreted a long time ago. However, another subsample of three N- and Al-rich stars with Mg-deficiency are kinematically consistent with the inner stellar halo. A speculative scenario to explain the origin of the atypical chemical composition of these stars in the inner halo is that they migrated to the inner stellar halo as unbound stars due to the mechanism of bar-induced resonant trapping.
- Publication:
-
SF2A-2017: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics
- Pub Date:
- December 2017
- DOI:
- 10.48550/arXiv.1710.07433
- arXiv:
- arXiv:1710.07433
- Bibcode:
- 2017sf2a.conf..199F
- Keywords:
-
- abundances;
- Population II;
- globular clusters;
- structure;
- formation;
- bulge;
- disk;
- kinematics and dynamics;
- numerical methods;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- To appear in the proceedings of the SF2A-2017, Paris, 4-7 July 2017