Probing Dust Settling in Proto-planetary Disks with ALMA

¹ Centro de Radioastronomia y Astrofisica, UNAM, Apartado Postal 3-72, 58089 Morelia, Michoacan, Mexico
² Univ. Bordeaux, LAB, UMR 5804, F-33270, Floirac, France
³ CNRS, LAB, UMR 5804, F-33270 Floirac, France
⁴ IRAM, 300 rue de la Piscine, 38400 Saint Martin d’H‘eres, France

^a e-mail: y.boehler@crya.unam.mx

Abstract

Investigating the dynamical evolution of dust grains in proto-planetary disks is a key issue to understand how planets should form. We identify under which conditions dust settling can be constrained by high angular resolution ALMA observations at mm wavelengths, and which observational strategies are suited for such studies. We find out that an angular resolution better than or equal to » 0.1” (using 2.3 km baselines at 0.8mm) allows us to constrain the dust scale height and flaring index with sufficient precision to unambiguously distinguish between settled and non-settled disks, provided the inclination is close enough to edge-on (i > 75°). Ignoring dust settling and assuming hydrostatic equilibrium when analyzing such disks biase the derived dust temperature, the radial dependency of the dust emissivity index and the surface density distribution.