演講資訊

摘要：

The outskirt of a disk galaxy is critically important because the secular evolution may significantly affect the properties of the disk outskirt. The outskirt of the Milky Way, in particular, can be better studied since we are able to measure the kinematics for individual stars in our Galaxy. The on-going LAMOST Milky Way spectroscopic survey has collected more than 5 million stellar spectra in the past four years, most of these data well cover the Galactic anti-center region. In this presentation, I will demonstrate the age variation of the stellar warp of the Milky Way unveiled from the LAMOST red clump stars located from 8 kpc to 14 kpc. The younger stellar warp displays larger vertical amplitude than the old one, in agreement with the misaligned gas infalling scenario of the formation of the warp. Although the tidal mechanisms of the warp formation can not be completely ruled out, it is quite challenging for these scenarios to reproduce such a age variation in the warp. The younger stellar population is also evident that its radial velocity is the perturbed by the spiral arms and hence show different bulk motions at different radii.