SETI public: Modeling the Jovian subnebula: I - Thermodynamical conditions and migration of p

Title: Modeling the Jovian subnebula: I - Thermodynamical conditions and
migration of proto-satellites

Authors: Yann Alibert, Olivier Mousis, and Willy Benz
Comments: Accepted in Astronomy and Astrohpysics
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We have developed an evolutionary turbulent model of the Jovian subnebula
consistent with the extended core accretion formation models of Jupiter
described by Alibert et al. (2005b) and derived from Alibert et al.
(2004,2005a). This model takes into account the vertical structure of the
subnebula, as well as the evolution of the surface density as given by an
$\alpha$-disk model and is used to calculate the thermodynamical conditions in
the subdisk, for different values of the viscosity parameter. We show that the
Jovian subnebula evolves in two different phases during its lifetime. In the
first phase, the subnebula is fed through its outer edge by the solar nebula as
long as it has not been dissipated. In the second phase, the solar nebula has
disappeared and the Jovian subdisk expands and gradually clears with time as
Jupiter accretes the remaining material. We also demonstrate that early
generations of satellites formed during the beginning of the first phase of the
subnebula cannot survive in this environment and fall onto the proto-Jupiter.
As a result, these bodies may contribute to the enrichment of Jupiter in heavy
elements. Moreover, migration calculations in the Jovian subnebula allow us to
follow the evolution of the ices/rocks ratios in the proto-satellites as a
function of their migration pathways. By a tempting to reproduce the distance
distribution of the Galilean satellites, as well as their ices/rocks ratios, we
obtain some constraints on the viscosity parameter of the Jovian subnebula.

\\ ( http://arXiv.org/abs/astro-ph/0505367 , 143kb)