Speaker
Prof.
Ji Li
(Department of Space Science and Astronomy, Hebei Normal University)
Description
The Galactic disk is the main structural component of the Milky Way, but whether there is a sub-structure of the so-called thin- and thick- disks has always been a controversial issue. Using the stellar spectra from the LAMOST Spectroscopic Survey of the Galactic Anti-center (LSS-GAC), we obtained the distributions of [α/Fe] ratios in the R-z space for about 1 800 000 disk stars from the DR4 of LAMOST, connecting with the star kinematics characteristics. The results indicate that the Galactic disk truly consist of two substructures with different [α/Fe] abundances, but there is no a distinct separation between the thin and thick disk (not in metallicity or the [α/Fe] ratios, nor in the space position). Moreover, there is an apparent “warp” in the edge of the Galactic disk.
Primary author
Prof.
Ji Li
(Department of Space Science and Astronomy, Hebei Normal University)
Co-authors
Prof.
Jianrong Shi
(National Astronomical Observatories, Chinese Academy of Sciences)
Dr
Maosheng Xiang
(NAOC)
Shuhua Jia
(Department of Space Science and Astronomy, Hebei Normal University, Shijiazhuang 050024, China)
Xiaowei Liu
(Department of Astronomy, Peking University, Beijing 100871, China)
Xuan Ci
(Department of Space Science and Astronomy, Hebei Normal University, Shijiazhuang 050024, China)