Do Centaurs preserve their source inclinations?

TL;DR

This paper investigates how close encounters with giant planets influence the inclination distribution of Centaurs, showing that their inclinations tend to cluster around 10-20 degrees regardless of initial conditions, and that the Kuiper belt is unlikely to be their source of retrograde objects.

Contribution

The study demonstrates that planetary encounters significantly shape the inclination distribution of Centaurs, challenging previous assumptions about their source regions.

Findings

Inclination distribution peaks near 10-20 degrees due to planetary encounters.

Kuiper belt is an unlikely source of retrograde Centaurs.

Initial inclination distributions are largely overwritten by planetary interactions.

Abstract

The Centaurs are a population of small, planet-crossing objects in the outer solar system. They are dynamically short-lived and represent the transition population between the Kuiper belt and the Jupiter family short-period comets. Dynamical models and observations of the physical properties of the Centaurs indicate that they may have multiple source populations in the trans-Neptunian region. It has been suggested that the inclination distribution of the Centaurs may be useful in distinguishing amongst these source regions. The Centaurs, however, undergo many close encounters with the giant planets during their orbital evolution; here we show that these encounters can substantially determine the inclination distribution of the Centaurs. Almost any plausible initial inclination distribution of a Kuiper belt source results in Centaurs having inclinations peaked near 10-20 degrees. Our studies also find that the Kuiper belt is an extremely unlikely source of the retrograde Centaur that has been observed.