The debris disk - terrestrial planet connection

TL;DR

This paper uses numerical simulations to explore how giant planet instabilities influence debris disks and terrestrial planet formation, suggesting observable debris disks indicate stable environments likely to host terrestrial planets.

Contribution

It demonstrates the correlation between giant planet dynamics, debris disks, and terrestrial planet formation, providing a predictive link between observable disks and planetary system stability.

Findings

Strong instabilities clear out inner and outer regions.

Stable systems with low-mass giants form terrestrial planets.

Bright debris disks indicate dynamically calm environments.

Abstract

The eccentric orbits of the known extrasolar giant planets provide evidence that most planet-forming environments undergo violent dynamical instabilities. Here, we numerically simulate the impact of giant planet instabilities on planetary systems as a whole. We find that populations of inner rocky and outer icy bodies are both shaped by the giant planet dynamics and are naturally correlated. Strong instabilities -- those with very eccentric surviving giant planets -- completely clear out their inner and outer regions. In contrast, systems with stable or low-mass giant planets form terrestrial planets in their inner regions and outer icy bodies produce dust that is observable as debris disks at mid-infrared wavelengths. Fifteen to twenty percent of old stars are observed to have bright debris disks (at wavelengths of ~70 microns) and we predict that these signpost dynamically calm environments that should contain terrestrial planets.