Institute for Advanced Study Informal Astrophysics Seminar

Observations of circumstellar debris disks have revealed that a subset of this population harbor a warm dust component. This dust is short-lived, requiring continual replenishment, and indicating that the disk must be excited by an unseen perturber. Previous theoretical studies have demonstrated that an eccentric planet orbiting interior to the disk will stir the planetesimals in the belt and produce dust via collisions. However, motivated by recent observations, we explore another possible mechanism for heating a debris disk: a stellar-mass perturber orbiting exterior to and inclined to the disk and exciting the planetesimals’ eccentricities and inclinations via the Kozai-Lidov mechanism. We explore the consequences of an exterior perturber on the evolution of a debris disk using secular analysis and collisional N-body simulations. We demonstrate that a Kozai-Lidov excited disk can generate a dust disk via collisions and compare the results of the Kozai-Lidov excited disk with a simulated disk perturbed by an interior eccentric planet. Finally, we discuss possible observational tests of a warm disk that can distinguish whether the disk was produced by an exterior brown dwarf or stellar companion or an interior planet.