English

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

Astrophysics of Galaxies 2023-10-17 v1

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 ZZ and VZV_Z distributions of stars with respect to LZL_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=60.0\Omega_{b}= 60.0 km s1 kpc1km~s^{-1}~kpc^{-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 RR and ZZ -- directions at large distances from the resonance region. Simulations, however, do not demonstrate any noticeable effect on VZV_Z-distribution of stars in the solar neighborhood

Keywords

Cite

@article{arxiv.2310.10327,
  title  = {Resonant Effects of a Bar on the Galactic Disk Kinematics Perpendicular to Its Plane},
  author = {Vladimir Korchagin and Artem Lutsenko and Roman Tkachenko and Giovanni Carraro and Katherine Vieira},
  journal= {arXiv preprint arXiv:2310.10327},
  year   = {2023}
}

Comments

21 pages, 12 figures