EDP Sciences
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Volume 373, Number 2, July II 2001
Page(s) 683 - 701
Section Formation and evolution of planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20010517

A&A 373, 683-701 (2001)
DOI: 10.1051/0004-6361:20010517

Short-term collisional evolution of a disc perturbed by a giant-planet embryo

S. Charnoz1, P. Thébault2 and A. Brahic1

1  Université Paris 7 Denis Diderot, Service d'Astrophysique & CEA Saclay, France
2  DESPA, Observatoire de Paris, 92195 Meudon Cedex Principal, France

(Received 26 December 2000 / Accepted 9 April 2001)

A simple numerical model has been developed to study the evolution of a disc of planetesimals under mutual inelastic collisions in the potential field of a central body and of an embedded giant-planet embryo. Masses for the latter range from 0.5 to 300 Earth masses. A mass of $15 M_{\oplus} $ is typical of the solid-core model for the formation of giant planets. The initially cold disc consists of a few thousand particles. Those initially present between one and three Hill radii from the perturber's orbit are transferred to very eccentric orbits causing violent collisions throughout the disc. The perturbation propagates far from the perturber, like a heat transfer: a $15 M_{\oplus} $ perturber orbiting at 5.2 a.u. heats up the disc from 2.3 to at least 11 a.u. from the central body in a few 105 to 106 years. Relative velocities are typically increased by a factor of 10 to 100. The extent of the heated region increases with the protoplanet's mass while the propagation timescale decreases. The resulting radial mixing has potential applications for the origin of the Asteroid Belt, in particular for the radial distribution of the asteroid's spectroscopic families.

Key words: Solar System: formation -- planets ans satellites: general -- minor planets, asteroid

Offprint request: S. Charnoz, charnoz@discovery.saclay.cea.fr

© ESO 2001