Special talk on Dec. 15th, 2017: The Stellar Kinematics in Our Milky Way

Speaker: 田海俊（三峡大学）/ Haijun Tian (China Three Gorges University)
Venue: Gewu 4410
Time: 11:00 AM, Friday, 15th December

Abstract:

With surveys such as LAMOST, Gaia, Pan-STARRS1 deep going, the researcheson our Milky Way has been stepping into a golden era. The massive stellar observations make the fine depiction of the kinematical features in our Milky Way to be of great interest in therecent years. In 2015, we used about 200,000 FGK-type main-sequence stars from the LAMOST DR1 to map the local stellar kinematics, found that the stellar kinematics are temperate and disc height dependent. With the cooler stars, which have been dynamically relaxed, we derive the solar motion of (U, V, W) = (9.58, 10.52, 7.01) km/s with respect to the local standard of rest (Tian et al. 2015). Last year, we presented the peculiar in-plane velocities derived from the LAMOST red clump stars (RCs), which are purified and separated  by a novel approach into two groups with different ages. With the two stellar populations, we found that both radial and azimuthal velocities are not axisymmetric at $8<R<14$\,kpc, and determined the pattern speed of the bar to be ~45 km/s/kpc (Tian et al. 2017a). Several month ago, we released a promising large proper motion catalog dubbed GPS1. To build this catalog, we combine Gaia DR1, PS1, SDSS and 2MASS astrometry, and measure proper motions for ~350 million sources across three-fourths of the sky down to a magnitude of mr~20mag. This catalog has a characteristic systematic error of less than 0.3 mas/yr, and a typical precision of 1.5-2.0 mas/yr (Tian et al. 2017b). In my talk, I will review the above three works in detail, and expect to seek for the collaboration, and get some constructive feedbacks.

Speaker Introduction:

田海俊：三峡大学副教授，理学院副院长，硕士生导师，曾连续三年入选LAMOST Fellow，2014年入选三峡大学“151”学术带头人、校“青年拔尖人才”。近年主要从事星系天文学、天文信息学、宇宙学等方面的课题研究。先后前往印度、美国、德国等知名大学或研究机构访学。主持国家基金两项，参与国家重点基金一项，发表学术论文20余篇。