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.
Highlights
Grain growth and dust settling are two key ingredients in the planets formation process
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” 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◦)
We study the impact of dust settling on the disk imaging at mm wavelengths, in order to define adequate observational strategies to constrain this phenomenon with ALMA
Summary
Grain growth and dust settling are two key ingredients in the planets formation process. Settling will speed up the growth process by favouring grain collisions, firstly by increasing the relative vertical velocities, as settling acts differently in function of the dust dynamic properties [1], and secondly by concentrating dust close to the midplane. A high dust to gas ratio in this area, can affect the gravitational stability and control the initial step of the formation of planetesimals [2]. Contrary to other shortest wavelenghts, the moderate opacity of the mm/submm domain allows dust mass estimate and should probe material throughout the complete disk structure. We study the impact of dust settling on the disk imaging at mm wavelengths, in order to define adequate observational strategies to constrain this phenomenon with ALMA
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
