Analogous Experiments on the Stickiness of Micron-sized Preplanetary Dust
T. Poppe, J. ü Blum, rgen, T. Henning;
ApJ, 2000, 533, 454
ABSTRACT:In the early solar nebula, the formation of planetesimals and cometesimals is believed to be due to inelastic collisions of initially
micron-sized grains.
The collisions are caused by relative velocities due to
size-dependent interactions with the surrounding dilute gas.
The grain growth
process is determined by the velocity-dependent sticking efficiency upon
collisions.
Therefore, we performed experiments with eight samples of micron-sized
particles consisting of monodisperse silica spheres, of irregularly shaped
diamond, enstatite, and silicon carbide grains, and of silicon carbide
whiskers.
We determined the sticking probability and the energy loss upon bouncing
collisions by studying individual grain-target collisions in vacuum.
We found a
sticking probability higher than predicted by previous theoretical
work.
Grain size, roughness, and primarily grain shape, i.e., the difference of
spherical versus irregular grain shape, is important for the collisional
behavior, whereas the material properties are rather unimportant.
Our results
indicate that the preplanetary dust aggregation is more effective than
previously thought.
KEYWORDS: accretion, accretion disks, ism: dust, extinction, methods: laboratory, solar system: formation
PERSOKEY:dust, size distribution, ,
CODE: poppe2000