Artículos de revistas
The Origins of Young Stars in the Direction of the Leading Arm of the Magellanic Stream: Abundances, Kinematics, and Orbits
Fecha
2019Registro en:
Astrophysical Journal, Volumen 871, Issue 1, 2019,
15384357
0004637X
10.3847/1538-4357/aaf560
Autor
Zhang, Lan
Casetti-Dinescu, Dana I.
Bidin, Christian Moni
Méndez, Réne A.
Girard, Terrence M.
Vieira, Katherine
Korchagin, Vladimir I.
Van Altena, William F.
Zhao, Gang
Institución
Resumen
We explore the origins of the young B-type stars found by Casetti-Dinescu et al. at the outskirts of the Milky Way disk in the sky region of the Leading Arm of the Magellanic Stream. High-resolution spectroscopic observations made with the MIKE instrument on the Magellan Clay 6.5 m telescope for nine stars are added to the previous sample analyzed by Zhang et al. We compile a sample of 15 young stars with well-determined stellar types, ages, abundances, and kinematics. With proper motions from Gaia DR2 we also derive orbits in a realistic Milky Way potential.We find that our previous radial-velocity-selected Leading Arm candidates have substantial orbital angular momentum. The substantial amount of rotational component for these stars is in contrast with the near-polar Magellanic orbit, thus making it unlikely that these stars are members of the Leading Arm. There are four large-orbital-energy stars in our sample. The star