Oral Presentation

Investigate Dust Self-Scattering in the Young Protostellar Disk HH 212

Author(s): Ying-Chi Hu (NTHU), Zhe-Yu Daniel Lin ( University of Virginia), Chin-Fei Lee (ASIAA), Shih-Ping Lai (NTHU)

Presenter: Ying-Chi Hu (NTHU)

Dust grain growth in the early stage of star formation plays an important role of planet formation in extrasolar systems. However, the dust properties (e.g., composition, grain sizes, opacities, albedo, etc) in young stellar systems are still uncertain. Recent studies of the dust polarization detection in the Class 0 HH 212 disk in ALMA Band 7 (Lee et al. 2018a, 2021) suggested that there could be possible grain growth in the disk for the early planet formation. Here we aim to investigate this possible grain growth by modeling the continuum maps of the disk obtained in multiple wavelengths from 0.87 (ALMA Band 7) to 7mm (VLA Band Ka), using a parametrized flared disk model with a RADMC-3D radiative transfer code. We have derived the opacity and albedo of the dust in the disk. The value of dust albedo is ~0.3 in ALMA Bands 7 and 6, ~ 0.1 in ALMA band 3, and ~ 0 in VLA Band Ka. These values indicate that the contribution of dust self-scattering can not be ignored for dust polarization in ALMA Bands 7, 6 and the maximum grain size should be smaller than 75 μm in the HH 212 disk.