Modeling the Migration of Neptune and the Corresponding Resonant Captures

TL;DR

This paper presents a semi-analytic model of Neptune's outward migration and resonant captures of Kuiper belt objects, explaining current orbital configurations and population ratios based on initial conditions and migration processes.

Contribution

It introduces a novel semi-analytic model that simulates Neptune's migration and resonant captures, linking initial KBO distribution to current observations.

Findings

The model explains Neptune's current semi-major axis and eccentricity.

Population ratios between 3:2 and 2:1 resonances depend on initial KBO density.

Original KBO distribution influences current resonant populations.

Abstract

Due to the angular momentum exchange with planetesimals, Neptune might have migrated outward to the current position, and captured many Kuiper belt objects (KBOs) into resonances. We set up a semi-analytic model to simulate the outward migration of Neptune, and the processes of resonant captures. Our model can naturally explain Neptune's currently observed semi-major axis and eccentricity. The results show that the current population ratio between 3:2 and 2:1 is mainly due to the original density distribution of KBOs, which might be related to drag-induced inward migrations of proto-KBOs.