Oral Presentation Astronomical Society of Australia Annual Scientific Meeting including HWWS 2013

Dust grain size sorting in the TW Hydrae protoplanetary disk (#47)

Christophe Pinte 1 , Francois Menard 1 , Maddison Sarah 2 , Pantin Eric 3 , Gonzalez Jean-Francois 4 , Ubach Catarina 2
  1. UMI-FCA Santiago, Santiago, Chile
  2. Swinburne, Melbourne, Australia
  3. CEA, Paris, France
  4. CRAL, Lyon, France

Proto-planetary disks are the birthplaces of planets. During the very first stages of planet formation, the dust particles grow by coagulation. In parallel, the gas drag on dust particles results in vertical settling and subsequent radial migration towards the central star. Dust migration and settling are central processes for the formation of planets as they concentrate material in the disk mid-plane and increase the local density, a necessary process for efficient dust grain growth and subsequent planet building. Hydrodynamical simulations show that radial migration of the dust is most efficient for grains of mm and cm sizes and should occur on timescales smaller than 100 000 years.

In this contribution, we present 7 mm observations of the disk surrounding the T Tauri star TW Hydra, obtained with the ATCA interferometer (and planned cycle 1 ALMA 3mm observations). These observations allow us to measure the full extension of the disk as well as its brightness profile. The comparison with data obtained at shorter wavelengths (850 microns, which probe the distribution of smaller grains), shows a less rapid falloff of the amplitude as a function of uv-distance, suggesting radial migration of mm/cm-sized grains. The analysis of these data, with state-of-the-art radiative transfer models, allows us to establish, for the first time, quantitative constraints on the degree of dust migration in a T Tauri disk. We discuss the implications of our findings on planet formation.