Planetesimal formation in self-gravitating discs -- dust trapping by vortices

Abstract

The mechanism through which meter-sized boulders grow to km-sized planetesimals in protoplanetary discs is a subject of active research, since it is critical for planet formation. To avoid spiralling into the protostar due to aerodynamic drag, objects must rapidly grow from cm-sized pebbles, which are tightly coupled to the gas, to large boulders of 1-100m in diameter. It is already well known that over-densities in the gaseous component of the disc provide potential sites for the collection of solids, and that significant density structures in the gaseous component of the disc (e.g., spiral density waves) can trap solids efficiently enough for the solid component of the disc to undergo further gravitational collapse due to their own self-gravity. In this work, we employ the PENCIL CODE to conduct local shearing sheet simulations of massive self-gravitating protoplanetary discs, to study the effect of anticyclonic transient vortices, or eddies, on the evolution of solids in these discs. We find that these types of structures are extremely efficient at concentrating small and intermediate-sized dust particles with friction times comparable to, or less than, the local orbital period of the disc. This can lead to significant over-densities in the solid component of the disc, with density enhancements comparable to, and even higher, than those within spiral density waves; increasing the rate of gravitational collapse of solids into bound structures.

13 pages, 9 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society. arXiv admin note: text overlap with arXiv:1404.6953

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Cited by in corpus (17)

• The early evolution of viscous and self-gravitating circumstellar disks with a dust component
• A thermodynamic view of dusty protoplanetary disks
• Collision velocity of dust grains in self-gravitating protoplanetary discs
• Dust capture and long-lived density enhancements triggered by vortices in 2D protoplanetary disks
• Gravito-turbulence and the excitation of small-scale parametric instability in astrophysical discs
• Characterizing gravito-turbulence in 3D: turbulent properties and stability against fragmentation
• Making Planet Nine: Pebble Accretion at 250--750 AU in a Gravitationally Unstable Ring
• The Maximum Mass Solar Nebula and the early formation of planets
• Dust dynamics in 2D gravito-turbulent disks
• The role of the drag force in the gravitational stability of dusty planet-forming disc -- II. Numerical simulations
• Dust dynamics and vertical settling in gravitoturbulent protoplanetary discs
• Spiral density waves and vertical circulation in protoplanetary discs
• The Concentration and Growth of Solids in Fragmenting Circumstellar Disks
• Vortex survival in 3D self-gravitating accretion discs
• The gas disk: Evolution and chemistry
• Ejection of Chondrules from Fluffy Matrices
• Effects of Outer Giant Planets on In Situ Formation of Inner Super-Earths