Speaker: Ewine F. van Dishoeck

　　Institute:Leiden Observatory, The Netherlands

　　Title: Zooming in on protoplanetary disks with ALMA

　　Time: 14：30-15:30 pm, Tuesday, 22 October, 2019

　　Location: Lecture Hall, 3rd floor, SHAO

　　Abstract:

　　Thanks to ALMA, the study of protoplanetary disks is undergoing a revolution, with a wide variety of results being reported on statistics of disks, fascinating substructures in dust and gas, and surprisingly weak CO emission. This talk will present a brief overview as well as recent results from our group and collaborators on ALMA observations and associated models of disks. First, the lateststatistics on disk masses in nearby star-forming regions will be presented, including low vs high mass regions, with implications for disk evolution. Second, the differences in sizes of gas vs dust disks will be discussed: do they indeed provide evidence for radial drift of mm-sized grains? Third, how do the large (transitional) disks with cavities and rings fit into the overall disk population? How strong is the evidence for just-formed planets in those disks?

　　Finally, the last part of the talk will provide a brief update of the IAU and its new strategic plan, and discuss the IAU 100 years centennial activities. See www.iau.org and www.iau-100.org.

--------------------------------------------------------------------------------------------------------

　　After Seminar's Discussion: 15:30-17:00, Room 303

　　Welcome!