Observations of gaseous debris disks

by Mr Gianni Cataldi (Department of Astronomy, Stockholm University)

Friday 5 Feb 2016, 10:30 → 11:30 Europe/Stockholm

FC61

Debris disks are the extrasolar analogues of the asteroid belt and the Kuiper belt in the solar system. In debris disks, dust is produced by collisional grinding of leftover planetesimals or comets. A fraction of debris disks show observable amounts of gas besides the dust. This gas is thought to be of secondary origin, i.e. produced from the dust. Thus, by observing the gas, we can learn more about the dust, and hence about the building blocks of exoplanets. In this talk, I will present work that will be part of the my upcoming PhD defense. I will discuss Herschel/HIFI observations of CII emission from the archetypal beta Pictoris debris disk. These observations were used to constrain the spatial distribution of the gas, which can tell us something about how the gas is produced. I also discuss observations of the Fomalhaut debris belt, where the absence of gas strongly suggests that gas-dust interactions are not effective in shaping the belt. Thus, yet unseen planet needs to be invoked in order to explain the morphology of the belt.