CONSTRAINING THE PLANETARY SYSTEM OF FOMALHAUT USING HIGH-RESOLUTION ALMA OBSERVATIONS

Abstract

The dynamical evolution of planetary systems leaves observable signatures in\ndebris disks. Optical images trace micron-sized grains, which are strongly\naffected by stellar radiation and need not coincide with their parent body\npopulation. Observations of mm-size grains accurately trace parent bodies, but\nprevious images lack the resolution and sensitivity needed to characterize the\nring's morphology. Here we present ALMA 350 GHz observations of the Fomalhaut\ndebris ring. These observations demonstrate that the parent body population is\n13-19 AU wide with a sharp inner and outer boundary. We discuss three possible\norigins for the ring, and suggest that debris confined by shepherd planets is\nthe most consistent with the ring's morphology.\n