Abstract
Trans-Neptunian objects (TNOs) orbit beyond Neptune and offer important clues on the origin and evolution of the solar system. We investigated the dynamical properties of 622 TNOs by performing computer simulations of their orbits plus several clones. We identified 196 TNOs locked in resonance with Neptune in the Edgeworth-Kuiper belt. Occupied resonances sorted by distance from the Sun are: 1:1, 5:4, 4:3, 11:8, 3:2, 18:11, 5:3, 12:7, 19:11, 7:4, 9:5, 11:6, 2:1, 9:4, 16:7, 7:3, 12:5, 5:2, 8:3, 3:1, 4:1, 11:2, and 27:4. Beyond 50AU, we examined the long-term evolution of 27 resonant TNOs by integrating their orbits over 4Gyr. The origin of 4Gyr-resident 9:4, 5:2, and 8:3 resonant TNOs was investigated using static and planetary migration dynamical models. We found that the long-term stable populations of 9:4, 5:2, and 8:3 resonant TNOs are well explained through adiabatic resonance capture by a migrating Neptune over a dynamically excited ancient trans-Neptunian belt. Therefore, this suggests that the primordial planetesimal disk had at least 47-50AU in radius, and suffered a dynamical perturbation leading to 0.1-0.3 or greater eccentricities and a range of inclinations up to ~20 degrees during early stages of the solar system's existence, before planetary migration.
