Bibcode
Li, Xiang; Wang, Hai-Feng; Luo, Yang-Ping; López-Corredoira, Martín; Ting, Yuan-Sen; Chrobáková, Žofia
Referencia bibliográfica
The Astrophysical Journal
Fecha de publicación:
2
2023
Revista
Número de citas
15
Número de citas referidas
14
Descripción
We present a Galactic disk vertical velocity analysis using OB type stars (OB stars), red clump (RC) stars, and main-sequence turnoff (MSTO) stars with different average age populations crossmatched with LAMOST DR5 and Gaia DR3. We show that the vertical velocities of the three populations clearly vary with the Galactocentric distance (R) and the younger stellar population has a stronger increasing trend in general. The bending and breathing modes indicated by the vertical motions are dependent on the populations and vary with spatial locations. These vertical motions may be due to the Galactic warp, or minor mergers, or nonequilibrium of the disk. Assuming the warp is the dominant component, we find that the amplitude of the warp (γ, Z ω ) of OB stars (younger population) is larger than that of RC stars (medium population) and the latter is also larger than that for MSTO stars (older population), which is in agreement with other independent analyses of stellar density distribution, and supports that the warp is a long-lived, nonsteady structure and is time evolving. This conclusion is robust whether the line of nodes ϕ w is fixed or is a free parameter (with ϕ w being around 3°-8.°5 as the best fit). Furthermore, we find that the warp is lopsided with asymmetries along the azimuthal angle (ϕ).
Proyectos relacionados
Vía Láctea y galaxias cercanas
El objetivo general del proyecto es el estudio de la morfología, poblaciones estelares, cinemática y dinámica (incluyendo formación y evolución) de la Vía Láctea y sus galaxias satélites u otras del Grupo Local. El proyecto puede dividirse en dos líneas principales: I. Estructura de la Vía Láctea y galaxias cercanas. El estudio detallado de la
Martín
López Corredoira