Simulating the Formation of Giant Planet Cores
Martin Duncan
Queen's University
Ironically, the most massive planets in the Solar System probably
formed in the least amount of time. Jupiter and Saturn must have
accreted their main constituents, hydrogen and helium, from the
solar nebula before it dispersed in the first few million years.
In the widely accepted core accretion model of giant planet
formation, a large solid planetary embryo of roughly 10 Earth masses
had to form first, mainly by accretion of much smaller bodies called
planetesimals. This was then followed by a period of inflow of
nebular gas directly onto the growing core. Assembling such a large
solid body so quickly, it turns out, offers some serious challenges
to the current theory of planet formation.
We (Levison, Thommes, Capobianco and I) are undertaking the most
comprehensive study of this problem to date, using numerical
integrations of the orbits of a number of Earth mass planetary
embryos embedded in a massive swarm of planetesimals. In these
experiments we have included simplified models of several physical
processes that have been suggested to solve the core accretion
problem. We find that in most of the simulations, gravitational
scattering leads to a wholesale redistribution of material and gap
formation around embryos, limiting their growth. Almost all cases of
large embryo growth were associated with self-sustaining outward
planetesimal-driven migration. Implications for giant planet
formation (including exoplanets) will be discussed.
Date: | Jeudi, le 10 septembre 2009 |
Heure: | 11:30 |
Lieu: | Université de Montréal |
| Pavillon Roger-Gaudry, Local D-460 |
Contact: | René Doyon |
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