Twisted debris: how differential secular perturbations shape debris disks

TL;DR

This paper models how unseen planets influence debris disk structures through secular perturbations and collisional evolution, helping interpret observations to infer planetary properties.

Contribution

It combines analytical and numerical models to predict observable features in debris disks caused by planetary perturbations, considering collisional and radiation effects.

Findings

Orbital element distributions depend on grain size.

Secular precession varies with semi-major axis and grain size.

Different wavelengths reveal distinct disk features.

Abstract

Resolved images suggest that asymmetric structures are a common feature of cold debris disks. While planets close to these disks are rarely detected, their hidden presence and gravitational perturbations provide plausible explanations for some of these features. To put constraints on the properties of yet undetected planetary companions, we aim to predict what features such a planet imprints in debris disks undergoing continuous collisional evolution. We discuss the basic equations, analytic approximations and timescales governing collisions, radiation pressure and secular perturbations. In addition, we combine our numerical model of the collisional evolution of the size and spatial distributions in debris disks with the gravitational perturbation by a single planet. We find that the distributions of orbital elements in the disks are strongly dependent on grain sizes. Secular precession is differential with respect to involved semi-major axes and grain sizes. This leads to observable differences between the big grains tracing the parent belt and the small grains in the trailing halo. Observations at different wavelengths can be used to constrain the properties of a possible planet.