PLANETESIMAL FORMATION BY GRAVITATIONAL INSTABILITY

@article{Youdin2002PLANETESIMALFB,
  title={PLANETESIMAL FORMATION BY GRAVITATIONAL INSTABILITY},
  author={A. Youdin and F. Shu},
  journal={The Astrophysical Journal},
  year={2002},
  volume={580},
  pages={494-505}
}
We investigate the formation of planetesimals via the gravitational instability of solids that have settled to the midplane of a circumstellar disk. Vertical shear between the gas and a subdisk of solids induces turbulent mixing that inhibits gravitational instability. Working in the limit of small, well-coupled particles, we find that the mixing becomes ineffective when the surface density ratio of solids to gas exceeds a critical value. Solids in excess of this precipitation limit can undergo… Expand

Figures and Tables from this paper

On the Formation of Planetesimals Via Secular Gravitational Instabilities with Turbulent Stirring
We study the gravitational instability (GI) of small solids in a gas disk as a mechanism to form planetesimals. Dissipation from gas drag introduces secular GI, which proceeds even when standard GIExpand
Rapid planetesimal formation in turbulent circumstellar disks
TLDR
It is reported that boulders can undergo efficient gravitational collapse in locally overdense regions in the midplane of the disk, and it is found that gravitationally bound clusters form with masses comparable to dwarf planets and containing a distribution of boulder sizes. Expand
Planetesimal Formation Through Streaming and Gravitational Instabilities
Planets form in circumstellar discs as dust grains collide together and form ever larger bodies. However a major bottleneck occurs for bodies with sizes around a few centimetres or larger. TheseExpand
Planetesimal formation by turbulent concentration
Abstract The formation of 1–1000 km diameter planetesimals from dust grains in a protoplanetary disk is a key step in planet formation. Conventional models for planetesimal formation involve pairwiseExpand
Gravitational instability and clustering in a disk of planetesimals
For a long time, gravitational instability in the disk of planetesimals has been suspected to be the main engine responsible for the beginning of dust growth, its advantage being that it provides forExpand
From Grains to Planetesimals
This pedagogical review covers an unsolved problem in the theory of protoplanetary disks: the growth of dust grains into planetesimals, solids at least a kilometer in size. I summarize timescaleExpand
Gravoturbulent Formation of Planetesimals
We explore the effect of magnetorotational turbulence on the dynamics and concentrations of boulders in local box simulations of a sub-Keplerian protoplanetary disk. The solids are treated asExpand
Forming Planetesimals by Gravitational Instability: I. The Role of the Richardson Number in Triggering the Kelvin-Helmholtz Instability
Gravitational instability (GI) of a dust-rich layer at the midplane of a gaseous circumstellar disk is one proposed mechanism to form planetesimals, the building blocks of rocky planets and gas giantExpand
FORMING PLANETESIMALS BY GRAVITATIONAL INSTABILITY. II. HOW DUST SETTLES TO ITS MARGINALLY STABLE STATE
Dust at the midplane of a circumstellar disk can become gravitationally unstable and fragment into planetesimals if the local dust-to-gas ratio μ0 ≡ ρd/ρg is sufficiently high. We simulate how dustExpand
Toward Planetesimals: Dense Chondrule Clumps in the Protoplanetary Nebula
We outline a scenario that traces a direct path from freely floating nebula particles to the first 10-100 km sized bodies in the terrestrial planet region, producing planetesimals that haveExpand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 49 REFERENCES
Secular Instability and Planetesimal Formation in the Dust Layer
Abstract Late in the gaseous phase of a protostellar disk, centimeter-sized bodies probably settle into a thin dust layer at the midplane. A velocity difference between the dust layer and the gasExpand
The formation of planetesimals.
Four stages in the accretion of planetesimals are described. The initial stage is the condensation of dust particles from the gaseous solar nebula as it cools. These dust particles settle into a thinExpand
Can Gravitational Instability Form Planetesimals
Abstract Gravitational instability of a particle layer in the solar nebula is inhibited by effects of the nebular gas. Particles must grow to at least meter size in order to decouple fromExpand
Collisional Cascades in Planetesimal Disks. I. Stellar Flybys
We use a new multiannulus planetesimal accretion code to investigate the evolution of a planetesimal disk following a moderately close encounter with a passing star. The calculations includeExpand
Possible Rapid Gas Giant Planet Formation in the Solar Nebula and Other Protoplanetary Disks.
  • Boss
  • Physics, Medicine
  • The Astrophysical journal
  • 2000
TLDR
New three-dimensional, "locally isothermal," hydrodynamical models without velocity damping show that a disk instability can form Jupiter-mass clumps, implying that disk instability could obviate the core accretion mechanism in the solar nebula and elsewhere. Expand
The formation of Uranus and Neptune in the Jupiter–Saturn region of the Solar System
TLDR
The results of model calculations are reported that demonstrate that solid cores of the gas-giant planets Jupiter and Saturn will have been gravitationally scattered outwards as Jupiter, and perhaps Saturn, accreted nebular gas. Expand
Photoevaporation of the Solar Nebula and the Formation of the Giant Planets
Abstract We review the prevailing theories for the formation of the jovian planets and comment that they do not provide a natural explanation for the oft-noted subdivision into two separate classes:Expand
Gravitational instabilities in a dust-gas layer and formation of planetesimals in the solar nebula
Dust particles which are initially distributed homogeneously in the solar nebula aggregate and settle towards the equatorial plane. As a result, the solar nebula separate into three layers: anExpand
Particle-Gas Dynamics in the Midplane of a Protoplanetary Nebula
Abstract In this paper, we study the stage of planetary formation during which the particulate material is still dispersed as centimeter-to-meter sized primordial aggregates. During this stage,Expand
The effect of long-lived vortical circulation on the dynamics of dust particles in the mid-plane of a protoplanetary disc
We investigate the response of dust particles in the mid-plane of a protoplanetary disc to the turbulent velocity field of long-lived, large-scale vortical circulation. The dynamical problem isExpand
...
1
2
3
4
5
...