Jeremy Lebreton (IPAC) - From cold debris disks to hot exozodis: observations and modeling

Dusty debris disks surrounding other stars than the Sun are thought to be extrasolar analogues to the Solar System’s Kuiper belt and main asteroid belt. Their emission is best detected using far-infrared telescopes and they often exhibit structures that can be attributed to the dynamical influence of hidden planets. Characterization of the warmer component of these disks, inside of a few AU, is still limited to a handful of cases. In this talk I will present a detailed radiative transfer approach used to model observations of optically thin dust disks obtained from multiple instruments. The methodology is then applied to Herschel observations of HD 181327, a young (12 Myr) Sun-like star surrounded by a massive, 90 AU-wide debris belt, also imaged in scattered light by the Hubble Space Telescope. The inner counterparts of debris disks located close to the habitable zone are revealed by their near- to mid-infrared emission and can be assessed with the required accuracy and resolution using optical interferometers like the VLTI, CHARA and KIN. I will present results obtained for some famous debris disks "stars" (Fomalhaut, Vega, Beta Pictoris) and temptative explanations to the origin of their excess emission. I will finally propose research directions for further investigations of dusty planetary systems using new models and future instruments.