Resonant Effects of a Bar on the Galactic Disk Kinematics Perpendicular to Its Plane

Korchagin, Vladimir; Lutsenko, Artem; Tkachenko, Roman; Carraro, Giovanni; Vieira, Katherine

Keywords: Milky Way disk, kinematics, dynamics

Abstract

Detailed analysis of kinematics of the Milky Way disk in the solar neighborhood based on the GAIA DR3 catalog reveals the existence of peculiarities in the stellar velocity distribution perpendicular to the galactic plane. We study the influence of resonances—the outer Lindblad resonance and the outer vertical Lindblad resonance—of a rotating bar with stellar oscillations perpendicular to the plane of the disk, and their role in shaping the spatial and the velocity distributions of stars. We find that the Z and V_Z distributions of stars with respect to L_Z are affected by the outer Lindblad resonance. The existence of bar resonance with stellar oscillations perpendicular to the plane of the disk is demonstrated for a long (large semi-axis 5 kpc) and fast rotating bar with Ωb=60.0kms−1kpc−1. We show also that, in the model with the long and fast rotating bar, some stars in the 2:1 OLR region deviate far from their original places, entering the bar region. A combination of resonance excitation of stellar motions at the 2:1 OLR region together with strong interaction of the stars with the bar potential leads to the formation of the group of 'escapees', i.e., stars that deviate in R and Z—directions at large distances from the resonance region. Simulations, however, do not demonstrate any noticeable effect on V_Z-distribution of stars in the solar neighborhood.

Más información

Título de la Revista: Galaxies
Volumen: 11
Número: 5
Editorial: Multidisciplinary Digital Publishing Institute (MDPI)
Fecha de publicación: 2023
Página de inicio: 97
Página final: 115
Idioma: English
URL: https://doi.org/10.3390/galaxies11050097
Notas: SCOPUS Web of Science