Planetesimal formation via fragmentation in self-gravitating protoplanetary discs

Abstract

An unsolved issue in the standard core accretion model for gaseous planet formation is how kilometre-sized planetesimals form from, initially, micron-sized dust grains. Solid growth beyond metre sizes can be difficult both because the sticking efficiency becomes very small, and because these particles should rapidly migrate into the central star. We consider here how metre-sized particles evolve in self-gravitating accretion discs using simulations in which the gravitational influence of the solid particles is also included. Metre-sized particles become strongly concentrated in the spiral structures present in the disc and, if the solid to gas density ratio is sufficiently high, can fragment due to their own self-gravity to form planetesimals directly. This result suggests that planetesimal formation may occur very early in the star formation process while discs are still massive enough to be self-gravitating. The dependence of this process on the surface density of the solids is also consistent with the observation that extrasolar planets are preferentially found around high metallicity stars.

5 pages, Accepted for publication in MNRAS

Cited by in corpus (13)

• Dust dynamics during protoplanetary disc clearing
• Planet formation bursts at the borders of the dead zone in 2D numerical simulations of circumstellar disks
• Standing on the shoulders of giants: Trojan Earths and vortex trapping in low mass self-gravitating protoplanetary disks of gas and solids
• Embryos grown in the dead zone: Assembling the first protoplanetary cores in low mass self-gravitating circumstellar disks of gas and solids
• The potential for Earth-mass planet formation around brown dwarfs
• Growth and migration of solids in evolving protostellar disks I: Methods and Analytical tests
• The Thermal Regulation of Gravitational Instabilities in Protoplanetary Disks. IV. Simulations with Envelope Irradiation
• Co-Accretion of Chondrules and Dust in the Solar Nebula
• From discs to planetesimals I: evolution of gas and dust discs
• Vortices in self-gravitating gaseous discs
• Light-induced disassembly of dusty bodies in inner protoplanetary discs: implications for the formation of planets
• Eccentricity growth of planetesimals in a self-gravitating protoplanetary disc
• Supplementary Information for ``Rapid planetesimal formation in turbulent circumstellar discs''