LiDO: Exploring the Stable Plutino Parameter Space

Abstract

We present a publicly available, high-resolution, filled-parameter-space synthetic distribution of the plutinos, trans-Neptunian objects (TNOs) librating in the 3:2 mean-motion resonance with Neptune, with particular focus on the plutinos simultaneously Kozai librating. This synthetic distribution was built in preparation for results from the Large inclination Distant Objects (L i DO) survey, which pointed at locations on the sky where Kozai plutinos are predicted to come to pericenter and are thus most easily detected in magnitude-limited surveys. Although we do not expect the full stable parameter space presented here to be populated with real TNOs, it provides a useful starting point for comparison with Neptune migration simulations and debiased observational results. Our new stable parameter-space synthetic distribution of fictitious plutinos is consistent with previous works, and we build on past results by focusing on the behavior of Kozai plutinos over 4 Gyr integrations. We find that 95% of 4 Gyr stable Kozai plutinos remain in the same ω -libration island for the entire integration. This provides an interesting diagnostic opportunity: any asymmetry in the true number of 4 Gyr stable Kozai plutinos in the two ω -libration islands must be caused by the details of emplacement during giant planet migration. Through analysis of previously published Neptune migration models, we show that the intrinsic fraction of plutinos captured into Kozai depends on Neptune’s migration speed and mode. Combining the filled-parameter-space synthetic distribution with future migration simulations and the results of the carefully characterized L i DO survey will enable interpretation of the intrinsic orbital distribution of the Kozai and non-Kozai plutinos.

Keywords

• Trans-Neptunian objects
• Kuiper belt
• Small Solar System bodies
• Plutoids
• Resonant Kuiper belt objects