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

Tkachenko, Roman; Carraro, Giovanni

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 (Formula presented.) distributions of stars with respect to (Formula presented.) 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 (Formula presented.). 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 (Formula presented.) -distribution of stars in the solar neighborhood. © 2023 by the authors.

Más información

Título según SCOPUS: Resonant Effects of a Bar on the Galactic Disk Kinematics Perpendicular to Its Plane
Título de la Revista: Galaxies
Volumen: 11
Número: 5
Editorial: Multidisciplinary Digital Publishing Institute (MDPI)
Fecha de publicación: 2023
Idioma: English
URL: https://doi.org/10.3390/galaxies11050097
DOI:

10.3390/galaxies11050097

Notas: SCOPUS - SCOPUS Web of Science