Eccentricity and Inclination of Massive Planets Inside Low-density Cavities: Results of 3D Simulations

TL;DR

This study uses 3D simulations to explore how massive planets inside low-density cavities of protoplanetary discs develop high eccentricities and inclinations through resonant interactions and Kozai-Lidov mechanisms, depending on their orbital tilt.

Contribution

It provides new insights into the dynamical evolution of planets in disc cavities, highlighting the roles of resonant interactions and Kozai-Lidov effects in eccentricity growth.

Findings

High eccentricities (0.7-0.9) can develop due to disc interactions.

Inclined orbits experience eccentricity growth via Kozai-Lidov mechanism.

Final eccentricity depends on planet mass and disc properties.

Abstract

We study the evolution of eccentricity and inclination of massive planets in low-density cavities of protoplanetary discs using three-dimensional (3D) simulations. When the planet's orbit is aligned with the equatorial plane of the disc, the eccentricity increases to high values of 0.7-0.9 due to the resonant interaction with the inner parts of the disc. For planets on inclined orbits, the eccentricity increases due to the Kozai-Lidov mechanism, where the disc acts as an external massive body that perturbs the planet's orbit. At small inclination angles, < 30 degrees, the resonant interaction with the inner disc strongly contributes to the eccentricity growth, while at larger angles, eccentricity growth is mainly due to the Kozai-Lidov mechanism. We conclude that planets inside low-density cavities tend to acquire high eccentricity if favorable conditions give sufficient time for growth. The final value of the planet's eccentricity, after the disc dispersal depends on the planet's mass and properties of the cavity and protoplanetary disc.