本学期学术活动

The stellar chemo-kinematics of the Galactic disk

2015-05-07    点击:

报告题目:The stellar chemo-kinematics of the Galactic disk

报 告 人:Chao Liu,NAOC

报告时间:2015年5月7日13:30-15:00

报告地点:报告摘要:Although the global picture of the Galactic disk has been well known for decades, lots of fundamental questions about the formation and evolution of the Galactic diskare still open. Only until recently, the large spectroscopic surveys, e.g. SDSS/SEGUE, SDSS III/APOGEE, and LAMOST, with a few hundreds thousands to a few million disk stars unveil more and more details of the disk, taking opportunities to answer some of the questions.

In this talk, I will demonstrate the recent observational chemo-kinematic features of the disk, which help us to better understand how the Galactic disk evolves. Firstly, the SDSS/SEGUIE G-type dwarf stars confirm that the disk is indeed affected by the radial migration, which have been proposed by theorists. The new LAMOST DR2 data reveals more concrete evidences, in the age-metallicity relation map, that when the radial migration occurred and at which radii it significantly mixed the stars. On the other hand, the new observational data also bring some, maybe more, puzzles. I will show you the complicated kinematic/dynamic features recently discovered in the outer disk, e.g., the bi-modalty of the radial velocity distribution in the Galactic anti-center region, the asymmetric bulk motions in both radial and vertical directions, and the strange oscillation in the disk rotation curve. All these evidences are opening new frontiers of the knowledge of the Galactic disk.