Direct Formation of Planetary Embryos in Self-gravitating Disks

Abstract Giant planets have been discovered at large separations from the central star. Moreover, a striking number of young circumstellar disks gas and/or dust gaps orbital separations, potentially driven by embedded planetary objects. To form massive through core accretion within disk lifetime, however, an early solid body to seed pebble and is desirable. Young protoplanetary are likely self-gravitating, these gravitoturbulent may efficiently concentrate material midplane spiral waves. We run 3D local hydrodynamical simulations with Lagrangian particles determine whether particle self-gravity can lead formation dense bodies, seeding later planet formation. When between included, solids size St = 0.1–1 features collapse under their own into clumps up several M ⊕ in mass wide orbits. Simulations that drift most efficiently, 1, clouds particles, while smaller 0.1, masses order magnitude lower. effect backreaction onto become factor few but more numerous. The existence bodies stage accelerate process, particularly explain distant stars substructures.