报告人：李兆聿 副研究员 （上海天文台）

时间：2016年3月1日下午4：00

地点：东区理化大楼18层天文台报告厅

报告摘要：Understanding the Milky Way structure is non-trivial, mostly because of our location in the disk. Living inside the Milky Way, we have the advantage to observe individual stars of this galaxy. This provides us a unique laboratory to study galaxy evolution in detail and in real time. In this talk, I will introduce recent progresses in Milky Way structure studies, which will focus on the structure and kinematic properties of the Galactic bulge and disk.

Recently, in the Galactic bulge, an intriguing ‘X’-shaped structure was found. Our group verified the connection of this X-shaped structure with the peanut-shaped bar, and studied the kinematic properties and 3D iso-density surfaces of this structure in detail. This is a clear signature that our Milky Way bulge is probably a pseudo-bulge, which was formed from the disk internal instability via the secular evolution.

The Milky Way disk is also full of mysteries. Observational evidences suggest that the disk is wobbly. Moreover, it even contains bending & breathing modes. I’ll describe our recent efforts in understanding these properties by combining observations and numerical simulations. We found that bar perturbation may have a small effect on the outer disk, while spiral arms may play a more important role here.