Quantification of stochastic fragmentation of self-gravitating discs

Abstract

Using 2D smoothed particle hydrodynamics, we investigate the distribution of wait times between strong shocks in a turbulent, self-gravitating accretion disc. We show the resulting distributions do not depend strongly on the cooling time or resolution of the disc and that they are consistent with the predictions of earlier work (Young & Clarke 2015; Cossins et al. 2009, 2010). We use the distribution of wait times between shocks to estimate the likelihood of stochastic fragmentation by gradual contraction of shear-resistant clumps on the cooling time scale. We conclude that the stochastic fragmentation mechanism (Paardekooper 2012) cannot change the radius at which fragmentation is possible by more than ~20%, restricting direct gravitational collapse as a mechanism for giant planet formation to the outer regions of protoplanetary discs.

Accepted for publication in MNRAS. 6 pages and 3 figures

References in corpus (5)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Inviscid SPH
• Characterising the Gravitational Instability in Cooling Accretion Discs
• Properties of gravitoturbulent accretion disks
• 3D Radiative Hydrodynamics for Disk Stability Simulations: A Proposed Testing Standard and New Results

Cited by in corpus (24)

• Gravitational Instabilities in Circumstellar Disks
• On the diversity and statistical properties of protostellar discs
• The SPHERE infrared survey for exoplanets (SHINE). III. The demographics of young giant exoplanets below 300 au with SPHERE
• The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits. IV. Gravitational instability rarely forms wide, giant planets
• The statistical properties of stars and their dependence on metallicity
• Towards a population synthesis model of self-gravitating disc fragmentation and tidal downsizing II: The effect of fragment-fragment interactions
• The importance of magnetic fields for the initial mass function of the first stars
• A revised condition for self-gravitational fragmentation of protoplanetary disks
• Dawes Review. The tidal downsizing hypothesis of planet formation
• The chemistry of protoplanetary fragments formed via gravitational instabilities
• Grand challenges in protoplanetary disc modelling
• On the gravitational stability of gravito-turbulent accretion disks
• Characterizing gravito-turbulence in 3D: turbulent properties and stability against fragmentation
• On the fragmentation boundary in magnetised self-gravitating discs
• The Effect of Protoplanetary Disk Cooling Times on the Formation of Gas Giant Planets by Gravitational Instability
• Fragmentation favoured in discs around higher mass stars
• The evolution of self-gravitating accretion discs
• The impact of numerical oversteepening on the fragmentation boundary in self-gravitating disks
• The Effect of the Approach to Gas Disk Gravitational Instability on the Rapid Formation of Gas Giant Planets
• Gravito-turbulence in local disk simulations with an adaptive moving mesh
• DIPSY: A new Disc Instability Population SYnthesis, II. The Populations of Companions Formed Through Disc Instability
• On fragmentation of turbulent self-gravitating discs in the long cooling time regime
• Planets, debris and their host metallicity correlations
• Structure of radiation dominated gravitoturbulent quasar discs