Mapping the Galactic disk with the LAMOST and Gaia red clump sample: IV: the kinematic signature of the Galactic warp

Abstract

Using a sample of nearly 140,000 red clump stars selected from the LAMOST and Gaia Galactic surveys, we have mapped mean vertical velocity $\overline{V_z}$ in the $X$-$Y$ plane for a large volume of the Galactic disk (6 $<R<16$ kpc; $-20<\varphi <50^{\circ }$; $|Z|<1$ kpc). A clear signature where $\overline{V_z}$ increases with $R$ is detected for the chemically thin disk. The signature for the thick disk is however not significant, in line with the hot nature of this disk component. For the thin disk, the warp signature shows significant variations in both radial and azimuthal directions, in excellent agreement with the previous results of star counts. Fitting the two-dimensional distribution of $\overline{V_z}$ with a simple long-lived static warp model yields a line-of-node angle for this kinematic warp of about $12.5^{\circ }$, again consistent with the previous results.

6 pages, 5 figures, ApJ accepted

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Cited by in corpus (10)

• Exploring the Galactic Warp Through Asymmetries in the Kinematics of the Galactic Disk
• Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample VII: the Stellar Disk Structure Revealed by the Mono-abundance Populations
• The Fornax3D project: Assembly histories of lenticular galaxies from a combined dynamical and population orbital analysis
• Local Stellar Kinematics and Oort Constants from the LAMOST A-type Stars
• Dynamical model of the Milky Way using APOGEE and Gaia data
• A twisted and precessing Cepheid warp in the outer Milky Way disc
• Warp and flare of the old Galactic disc as traced by the red clump stars
• A slightly oblate dark matter halo revealed by a retrograde precessing Galactic disk warp
• Modeling the vertical distribution of the Milky Way's flat subsystem objects
• Azimuthal Misalignments in Stellar Warp Structure as Dynamical Tracers of Mergers in Milky Way-like Galaxies