Planet Embryos in Vortex Wombs

Abstract

One of the enduring puzzles in the formation of planetary systems is how millimeter‐sized dust grains agglomerate to become kilometer‐sized, self gravitating planetesimals, the “building blocks” of planets. One theory is that the dust grains settle into the mid‐plane of the protoplanetary disk (thin, cool disk of gas and dust in orbit around a newly forming protostar) until they reach a critical density that triggers a gravitational instability to clumping. However, turbulence within the disk is likely to stir up the dust grains and prevent them from reaching this critical density. A competing theory is that dust grains grow by pair‐wise collisions, forming fractal structures. It is unclear, however, how robust such structures would be to successive collisions. A new and exciting theory is that vortices in a protoplanetary disk may capture dust grains at their centers, “seeding” the formation of planetesimals. We are investigating the dynamics of 3D vortices in protoplanetary disks with a parallel spectra...