Planet-planet scattering in planetesimal disks

TL;DR

This study uses N-body simulations to explore how planet-planet and planetesimal interactions shape the final orbital architectures of planetary systems, revealing mass-dependent outcomes and resonance formations.

Contribution

It provides new insights into the combined effects of planet-planet and planetesimal scattering on planetary system evolution, including the formation of resonant chains and orbit circularization.

Findings

High-mass systems (>1 Jupiter mass) retain broad eccentricity distributions.

Lower-mass systems tend to have nearly circular final orbits.

Many systems evolve into resonant configurations, some resembling Jupiter's satellite system.

Abstract

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 system masses exceeding about one Jupiter mass the final eccentricity distribution remains broad, whereas for lower mass planetary systems 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 lead 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 5-10 AU.