Observing dust settling and coagulation in circumstellar discs: Selected constraints from high resolution imaging

TL;DR

This paper investigates how multi-wavelength high-resolution imaging can be used to identify dust grain growth and settling in circumstellar discs, crucial for understanding planet formation, by modeling and analyzing observational data.

Contribution

It provides criteria based on multi-wavelength imaging to detect dust grain growth and sedimentation, highlighting the effectiveness of millimetre/sub-millimetre data and limitations of infrared observations.

Findings

Millimetre and sub-millimetre images help constrain dust growth and sedimentation.

Infrared images face degeneracy issues in constraining disc parameters.

Face-on N and Q Band observations can estimate sedimentation height.

Abstract

Circumstellar discs are expected to be the nursery of planets. Grain growth within such discs is the first step in the planet formation process in the core-accretion gas-capture scenario. We aim at providing selected criteria on observational quantities derived from multi-wavelength imaging observations that allow to identify dust grain growth and settling. We define a wide-ranged parameter space of discs in various states of their evolution. Using a parametrised model set-up and radiative transfer techniques we compute multi-wavelength images of discs at different inclinations. Using millimetre and sub-millimetre images we are in the position to constrain the process of dust grain growth and sedimentation. However, the degeneracy between parameters prohibit the same achievement using near- to mid-infrared images. Using face-on observations in the N and Q Band, the sedimentation height can be constrained.