Can planetesimals form by collisional fusion?

Abstract

As a test bed for the growth of protoplanetary bodies in a turbulent circumstellar disk we examine the fate of a boulder using direct numerical simulations of particle seeded gas flowing around it. We provide an accurate description of the flow by imposing no-slip and non-penetrating boundary conditions on the boulder surface using the immersed boundary method pioneered by Peskin (2002). Advected by the turbulent disk flow, the dust grains collide with the boulder and we compute the probability density function (PDF) of the normal component of the collisional velocity. Through this examination of the statistics of collisional velocities we test the recently developed concept of collisional fusion which provides a physical basis for a range of collisional velocities exhibiting perfect sticking. A boulder can then grow sufficiently rapidly to settle into a Keplerian orbit on disk evolution time scales.

Astrophysical Journal, in press

References in corpus (2)

• Closed-form expressions for particle relative velocities induced by turbulence
• Turbulence Induced Collision Velocities and Rates between Different Sized Dust Grains

Cited by in corpus (8)

• Turbulence modulation in heavy-loaded suspensions of tiny particles
• Tailoring boundary geometry to optimize heat transport in turbulent convection
• Effect of turbulence on collisions of dust particles with planetesimals in protoplanetary disks
• Dust dynamics in 2D gravito-turbulent disks
• Erosion of planetesimals by gas flow
• A quantification of hydrodynamical effects on protoplanetary dust growth
• Planetesimals on eccentric orbits erode rapidly
• Inelastic accretion of inertial particles by a towed sphere