Asymmetric Drift Map of the Milky Way disk Populations between 8$-$16 kpc with LAMOST and Gaia datasets

The asymmetric drift (AD) tomography in different populations is helpful for us to better understand the disk kinematics, dynamics and rotation curves. Using the common stars from the LAMOST and Gaia surveys as well as circular velocity of Gaia DR3, we qualitatively explore the asymmetric drift distributions of the Galactic disk from 8$-$16\,kpc. In the $R-Z$ plane, we find that the asymmetric drift near the mid-plane of the Galactic disk is small and gradually increases with the vertical distance, which makes the asymmetric drift appear as a ``horn'' shape. Meanwhile, we reveal that high [$\alpha$/Fe] populations have larger asymmetric drift than that in the low [$\alpha$/Fe] populations. The asymmetric drift around the solar location V$_a$ = 6 km s$^{-1}$ and the asymmetric drift median value of the whole sample is 16 km s$^{-1}$. Moreover, we also find that the asymmetric drift median value in the north (20 km s$^{-1}$) of the Galactic disk is larger than that in the south (13 km s$^{-1}$), all errors are within 2 km s$^{-1}$. Furthermore, when we investigate the asymmetric drift of the Galactic disk in the mono-age stellar populations, it shows that the older stellar populations have larger asymmetric drift and velocity dispersion which are almost consistent with predictions of previous numerical models. Finally, based on the chemistry, we unveil that the median asymmetric drift of the thick disk is much higher than that of the thin disk.
Comment: 13 pages and 17 figures