DIX Planetary Science Seminar

Observations of protoplanetary disks are providing increasingly strong constraints on the dust and gas properties in protoplanetary disks (PPDs). These in turn have challenged our understanding of planet formation. For example, it is now known that PPDs exhibit rich features (such as rings, gaps, and vortices) even when the disks are relatively young (a fraction of a million years), posing the question whether multiple planets could form early. Meanwhile, large-scale numerical modeling of the joint dynamics of gas and dust in such disks has shown great progress over the past decade. In this talk, we will describe the new challenges emerging from observations and present the recent numerical studies in 3D global gas+dust two-fluid PPD simulations. We will use several examples to show how dust particles can grow in size and become concentrated, leading to excitation of various instabilities that could eventually lead to planetesimal formation. These extensive numerical studies are providing valuable understanding on how dust might behave in 3D realistic disks and offer critical insights on interpreting observations.