EDP Sciences
Free access
Volume 395, Number 2, November IV 2002
Page(s) 613 - 623
Section Formation and evolution of planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20021274

A&A 395, 613-623 (2002)
DOI: 10.1051/0004-6361:20021274

Planetesimal clusters in a Keplerian disk

I. gravitational evolution
P. Tanga1, P. Michel1 and D. C. Richardson2

1  Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 04, France
2  Dept. of Astronomy, Univ. of Maryland, College Park, MD 20742-2421, USA

(Received 6 May 2002 / Accepted 30 August 2002 )

It was recently demonstrated by numerical simulations that a turbulent flow in a rotating system is capable of efficiently concentrating passively advected particles - having a density larger than the fluid - inside anti-cyclonic vortices. This process has important consequences on the distribution of solid particles in protoplanetary disks, since dust surface densities ~1-2 orders of magnitude higher than the background are rapidly reached in vortex cores. However, until now, the role of self-gravitation of captured solids has been neglected. In this work we study the action of mutual gravitational interactions - after the gas has dissipated - over the dynamics of planetesimals inside clusters similar to those created in vortex cores. A comparison is made between the behavior of idealized clusters of planetesimals characterized by ad-hoc velocity profiles, and more complex initial conditions such as those obtained in previous hydrodynamical simulations. We show here that, within the explored interval of parameters, mutual scattering of particles can quickly disperse the cluster. Our results are demonstrated to be not dependent on the resolution employed. It can be concluded that if large planetesimals were formed inside vortex cores, they would be ejected by mutual perturbations.

Key words: planetary systems: formation, protoplanetary disks; gravitation

Offprint request: P. Tanga, tanga@obs-nice.fr

© ESO 2002