ABSTRACT

Planets appears commonplace in the Universe. However, the details of their formation remains a puzzle. The building blocks of planets are planetesimals, themselves formed from small dust grains immersed in a gaseous protoplanetary disk (PPD) surrounding young stars. Thus, understanding the dust-gas dynamics in PPDs lays the foundation to any theory of planet formation. I will present recent work on dust-gas dynamics in PPDs and discuss implications for planet formation. I first describe the problem of dust sedimentation in PPDs. This process is widely considered as a necessary step towards planetesimal formation. However, turbulence in the disk can stir up dust particles, thereby prevent planetesimal formation. I will discuss how dust can overcome turbulence and sediment by accounting for two-way drag forces between gas and dust. I will then describe how newly born protoplanets continue to interact with its surrounding disk. Such disk-planet interactions may be responsible for substructures such as rings and gaps now commonly observed in real PPDs. I show that planets interacting with a dusty disk can differ significantly from the more frequently studied case of pure gas disks. This may be important for shaping the final architecture of planetary systems. Finally, I will give a preview of upcoming projects that combine disk-planet interaction and dust settling in the context of PPD substructures. 

BIO
Min-Kai Lin (林明楷) is an Assistant Research Fellow at the Academia Sinica Institute of Astronomy and Astrophysics. He obtained both undergraduate and graduate degrees from the University of Cambridge in 2008 and 2011, respectively. Before returning to Taipei in 2016, he worked as a postdoctoral fellow at the Canadian Institute for Theoretical Astrophysics and as the Steward Theory Fellow at the University of Arizona. Min-Kai is interested in astrophysical fluid dynamics applied to the formation of planets and planetary systems. He studies the birthplace of planets — protoplanetary disks — using a variety of analytical and computational tools to model their evolution.