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Brownian motion growth: self-similar. Dullemond & Dominik 2005. Sedimentation-driven growth („rainshower“). One-particle model. Equator. Sedimentation-driven growth („rainshower“). One-particle model. Equator. Sedimentation-driven growth („rainshower“). One-particle model. Equator.
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Brownian motion growth: self-similar Dullemond & Dominik 2005
Sedimentation-driven growth („rainshower“) One-particle model Equator
Sedimentation-driven growth („rainshower“) One-particle model Equator
Sedimentation-driven growth („rainshower“) One-particle model Equator
Sedimentation-driven growth („rainshower“) One-particle model Equator Warning: Not to scale! ;-)
Sedimentation-driven growth („rainshower“) Equation of settling of the big dust grain: Equation of growth by sweep-up as the big grain falls: Relation between m(t) and a(t): Distribution of the small dust:
Sedimentation-driven growth („rainshower“) Dullemond & Dominik (2005)
“Rainshower” in a disk Dullemond & Dominik (2005)
Parallel with meteorology Rain falling from a cumulus congestus cloud
Now with convection Dullemond & Dominik (2005)
Parallel with meteorology Cumulonimbus cloud, most probably with severe hail
Parallel with meteorology Layered structure of giant hail stone
Main problem: high velocities 30 m/s = 100 km/h !! Particle size [meter]
Dust coagulation+fragmentation model 10-2 10-4 Σdust [g/cm2] 10-6 10-8 10-2 100 10-4 Grain size [cm] Birnstiel, Dullemond & Ormel 2010
Dust coagulation+fragmentation model 10-2 10-4 Σdust [g/cm2] 10-6 10-8 10-2 100 10-4 Grain size [cm] Birnstiel, Dullemond & Ormel 2010
Meter-size barrier Rapid radial drift Aggregation Fragmentation Sweep-up growth 1m 1km 1mm 1m Meter-size barrier Growth from ‘dust’ to planetary building blocks Brownian motion Differential settling Turbulence
Bouncing barrier Charge barrier Meter-size barrier Rapid radial drift Aggregation Fragmentation Sweep-up growth 1m 1km 1mm 1m More barriers... Growth from ‘dust’ to planetary building blocks Brownian motion Differential settling Turbulence Zsom et al. 2010, Güttler et al. 2010 Okuzumi 2009
Meter-size barrier Rapid radial drift Aggregation Fragmentation Sweep-up growth 1m 1km 1mm 1m The “Lucky One” idea Let’s focus on the fragmentation barrier Growth from ‘dust’ to planetary building blocks Brownian motion Differential settling Turbulence
The “Lucky One” idea Low sticking efficiency Particle abundance Windmark et al. 2012 Howtocreatetheseseeds? Perhapsvelocitydistributions: Garaud et al. 2013; Windmark et al. 2012
All the different collision outcomes... Güttler et al. 2010
Fluffy grains, compaction, bouncing... Zsom et al. 2010