Protostars and Planets VI, Heidelberg, July 15-20, 2013
Rossby-wave instability and planetesimal growth in protoplanetary disks
MEHEUT, Heloise (AIM, CEA-Saclay)
In the current formation theory, planets are supposed to be built from colliding planetesimals of kilometre or larger size, but the formation of these planetesimals is still an issue. Here we consider the presence of vortices formed by the Rossby wave instability (RWI, Lovelace et al. 1999). In this scenario the ‘meter size barrier’ is overstepped by the presence of vortices that concentrate solids in their centre and accelerate the growth process.
We perform global 3D simulations of a radially and vertically stratified disk. The first phase consists in the growth of the RWI in a gas disk. The dust is added, as a pressureless fluid, when the RWI has reached saturation (Meheut et al. 2012). Multiples grain sizes from 1mm to 5cm are used with a constant density distribution. Initially the solids density is axisymetric with a gas-to-dust density ratio of 10-2. We then follow the concentration of those solids in the 3D vortices. This process is very efficient and the dust density reaches the gas density on a timescale of only a few orbits.
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