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

• DOI: 10.33232/001c.117594
• Publication Date: 2024-05-14T07:47:57Z
• Authors: Xin Li; Peng Yang; Hai-Feng Wang; Qing Li; Yang-Ping Luo; Zhi-Quan Luo; Guan-Yu Wang
• Keywords: LAMOST

The application of asymmetric drift (AD) tomography across different populations provides valuable insights into the kinematics, dynamics, and rotation curves Galactic disk. By leveraging common stars identified in both LAMOST Gaia surveys, alongside DR3’s circular velocity curve, we conducted a qualitative exploration distributions within disk spanning distances from 8 to 16 kpc. In R-Z plane, observed that is minimal near mid-plane gradually increases with vertical distance, resulting distinctive “horn” shape. Additionally, our analysis revealed higher [ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>α</mml:mi></mml:math>/Fe] ratios exhibit greater compared those lower ratios. Specifically, found around solar location be approximately 6 km s display="inline"><mml:msup><mml:mi/><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>, median value display="inline"><mml:msup><mml:mi/><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math> entire sample. Notably, northern region (20 display="inline"><mml:msup><mml:mi/><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>) surpasses southern (13 display="inline"><mml:msup><mml:mi/><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>), errors remaining 2 display="inline"><mml:msup><mml:mi/><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>. Furthermore, investigation mono-age stellar unveiled older tend larger dispersion, aligning closely predictions previous numerical models. Finally, based on chemical compositions, thick significantly exceeds thin star formation primarily occurred 8-10 billion years ago, whereas disk’s predominant period spanned 6-8 ago.