Production of White Dwarf Debris Disks from Planetary Collisions and Poynting-Robertson Drag

This paper explores the production of debris disks around white dwarfs, which are observed to experience frequent pollution events. In this scenario, planetary collisions occur just outside the surface of a highly evolved AGB star, after the end of its mass loss phase, as it starts its transition into a white dwarf. The collisions vaporize a fraction of the planetary material, which subsequently expands, cools, nucleates droplets, and condenses into rocky bodies with characteristic size of order $s\sim 1$ cm. The rocky debris disk evolves through the action of Poynting-Robertson drag, driven by the stellar luminosity, which is initially large but steadily decreases with time. This scenario provides an alternate channel for delivering rocky material to the immediate vicinity of a white dwarf.