Tidal Debris Candidates from the ω Centauri Accretion Event and Its Role Building Up the Milky Way Halo

Anguiano, Borja; Mitschang, Arik W.; Kirihara, Takanobu; Hirai, Yutaka; Horta, Danny; Hasselquist, Sten; Schiavon, Ricardo P.; Majewski, Steven R.; Mason, Andrew C.; Price-Whelan, Adrian M.; Allende Prieto, Carlos; Smith, Verne V.; Cunha, Katia; Nidever, David L.
Referencia bibliográfica

The Astrophysical Journal

Fecha de publicación:
8
2025
Número de autores
14
Número de autores del IAC
1
Número de citas
2
Número de citas referidas
0
Descripción
We identify stellar tidal debris from the ω Centauri (ω Cen) system among field stars in the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey via chemical tagging using a neural network trained on APOGEE observations of the ω Cen core. We find a total of 463 ω Cen debris candidates have a probability P > 0.8 of sharing common patterns in their chemical abundances across a range of individual elements or element combinations, including [C+N], O, Mg, Al, Si, Ca, Ni, and Fe. Some debris candidates show prograde or retrograde disk-like kinematics, but most show kinematics consistent with the accreted halo, showing high radial actions, JR, values. We find that a sample of Gaia-Sausage-Enceladus (GES) members are chemically distinct from the ω Cen core, suggesting that ω Cen is associated with an independent merger event shaping the Milky Way halo. However, a connection between GSE and ω Cen cannot be ruled out. A detailed comparison with N-body simulations indicates that the ω Cen progenitor was a massive dwarf galaxy (≳108M⊙). The existence of a metal-poor high-α chemically homogeneous halo debris is also reported.
Proyectos relacionados
spectrum of mercury lamp
Abundancias Químicas en Estrellas
La espectroscopía de estrellas nos permite determinar las propiedades y composiciones químicas de las mismas. A partir de esta información para estrellas de diferente edad en la Vía Láctea es posible reconstruir la evolución química de la Galaxia, así como el origen de los elementos más pesados que el boro, forjados principalmente en los interiores
Carlos
Allende Prieto