Not a simple relationship between Neptune's migration speed and Kuiper belt inclination excitation

Abstract

We present numerical simulations of giant planet migration in our solar system and examine how the speed of planetary migration affects inclinations in the resulting population of small bodies (test particles) scattered outward and subsequently captured into Neptune's 3:2 mean motion resonance (the Plutinos) as well as the hot classical Kuiper belt population. We do not find a consistent relationship between the degree of test particle inclination excitation and e-folding planet migration timescales in the range 5-50 Myr. Our results present a counter-example to Nesvorny 2015's finding that the Plutino and hot classical inclinations showed a marked increase with increasing e-folding timescales for Neptune's migration. We argue that these differing results are likely due to differing secular architectures of the giant planets during and after migration. Small changes in the planets' initial conditions and differences in the numerical implementation of planet migration can result in different amplitudes of the planets' inclination secular modes, and this can lead to different final inclination distributions for test particles in the simulations. We conclude that the observed large inclination dispersion of Kuiper belt objects does not require Neptune's migration to be slow; planetary migration with e-folding timescales of 5, 10, 30, and 50 Myr can all yield inclination dispersions similar to the observed Plutino and hot classical populations, with no correlation between the degree of inclination excitation and migration speed.

accepted for publication in AJ

References in corpus (5)

• Origin of the Structure of the Kuiper Belt during a Dynamical Instability in the Orbits of Uranus and Neptune
• Tracking Neptune's Migration History through High-Perihelion Resonant Trans-Neptunian Objects
• A new paradigm for reproducing and analyzing N-body simulations of planetary systems
• The Warped Plane of the Classical Kuiper Belt
• Stability of the Outer Planets in Multiresonant Configurations with a Self-gravitating Planetesimal Disk

Cited by in corpus (11)

• Solar System Physics for Exoplanet Research
• OSSOS XX: The Meaning of Kuiper Belt Colors
• Eccentric Early Migration of Neptune
• Is There an Earth-like Planet in the Distant Kuiper Belt?
• Dynamical Implantation of Blue Binaries in the Cold Classical Kuiper Belt
• Stability of Neptune's distant resonances in the presence of Planet Nine
• A von Mises-Fisher Distribution for the Orbital Poles of the Plutinos
• On the Origin of the Pluto System
• Can the orbital distribution of Neptune's 3:2 mean motion resonance result from stability sculpting?
• Crash Chronicles: relative contribution from comets and carbonaceous asteroids to Earth's volatile budget in the context of an Early Instability
• Considering contact forces during the formation of planetesimals by gravitational collapse: mutual orbits, spin states, and shapes