We study the final architecture of planetary systems that evolve under the combined effects of planet–planet and planetesimal scattering. Using N-body simulations we investigate the dynamics of marginally unstable systems of gas and ice giants both in isolation and when the planets form interior to a planetesimal belt. The unstable isolated systems evolve under planet–planet scattering to yield an eccentricity distribution that matches that observed for extrasolar planets. When planetesimals are included the outcome depends upon the total mass of the planets. For Mtot ≳ 1 MJ the final eccentricity distribution remains broad, whereas for Mtot ≲ 1 MJ a combination of divergent orbital evolution and recircularization of scattered planets results in a preponderance of nearly circular final orbits. We also study the fate of marginally stable multiple planet systems in the presence of planetesimal disks, and find that for high planet masses the majority of such systems evolve into resonance. A significant fraction leads to resonant chains that are planetary analogs of Jupiter's Galilean satellites. We predict that a transition from eccentric to near-circular orbits will be observed once extrasolar planet surveys detect sub-Jovian mass planets at orbital radii of a ≃ 5–10 AU.
BT - The Astrophysical Journal DA - 2009-07 DO - 10.1088/0004-637X/699/2/L88 N2 -We study the final architecture of planetary systems that evolve under the combined effects of planet–planet and planetesimal scattering. Using N-body simulations we investigate the dynamics of marginally unstable systems of gas and ice giants both in isolation and when the planets form interior to a planetesimal belt. The unstable isolated systems evolve under planet–planet scattering to yield an eccentricity distribution that matches that observed for extrasolar planets. When planetesimals are included the outcome depends upon the total mass of the planets. For Mtot ≳ 1 MJ the final eccentricity distribution remains broad, whereas for Mtot ≲ 1 MJ a combination of divergent orbital evolution and recircularization of scattered planets results in a preponderance of nearly circular final orbits. We also study the fate of marginally stable multiple planet systems in the presence of planetesimal disks, and find that for high planet masses the majority of such systems evolve into resonance. A significant fraction leads to resonant chains that are planetary analogs of Jupiter's Galilean satellites. We predict that a transition from eccentric to near-circular orbits will be observed once extrasolar planet surveys detect sub-Jovian mass planets at orbital radii of a ≃ 5–10 AU.
PY - 2009 SP - L88 EP - L92 T2 - The Astrophysical Journal TI - Planet-Planet Scattering in Planetesimal Disks VL - 699 SN - 0004-637X ER -