On the observability of resonant structures in planetesimal disks due to planetary migration

TL;DR

This study investigates how planetary migration influences the formation and observability of resonant structures in planetesimal disks, highlighting the sensitivity to initial conditions and planetary eccentricity.

Contribution

It provides a comprehensive numerical analysis of the effects of planetary migration on debris disk structures, extending previous analytical work and offering visual disk models.

Findings

Resonant structures are highly sensitive to planetary eccentricity.

Even small planetary eccentricities can erase observable resonant features.

Initial low eccentricity of planetesimals is crucial for visible resonant clumps.

Abstract

We present a thorough study of the impact of a migrating planet on a planetesimal disk, by exploring a broad range of masses and eccentricities for the planet. We discuss the sensitivity of the structures generated in debris disks to the basic planet parameters. We perform many N-body numerical simulations, using the symplectic integrator SWIFT, taking into account the gravitational influence of the star and the planet on massless test particles. A constant migration rate is assumed for the planet. The effect of planetary migration on the trapping of particles in mean motion resonances is found to be very sensitive to the initial eccentricity of the planet and of the planetesimals. A planetary eccentricity as low as 0.05 is enough to smear out all the resonant structures, except for the most massive planets. The planetesimals also initially have to be on orbits with a mean eccentricity of less than than 0.1 in order to keep the resonant clumps visible. This numerical work extends previous analytical studies and provides a collection of disk images that may help in interpreting the observations of structures in debris disks. Overall, it shows that stringent conditions must be fulfilled to obtain observable resonant structures in debris disks. Theoretical models of the origin of planetary migration will therefore have to explain how planetary systems remain in a suitable configuration to reproduce the observed structures.