Oral Presentation

Early Planet Formation in Embedded Disks (eDisk): 3 mm Continuum Observations and Radiative Transfer Modeling

Author(s): Youngwoo Choi, Woojin Kwon, and eDisk team

Presenter: Youngwoo Choi (Seoul National University)

We present ALMA Band 3 (3.1 mm) continuum observations of Class 0/I disks in the Early Planet Formation in Embedded Disks (eDisk) sample at an angular resolution of ~0.05". Radiative transfer modeling of the eDisk sample is carried out to fit both ALMA Band 6 (1.3 mm) and Band 3 (3.1 mm) continuum images simultaneously. Our best-fit models that include dust self-scattering successfully reproduce both the 1.3 mm and 3.1 mm observations. Assuming moderate dust absorption opacities, the inferred dust masses are several hundred to a thousand Earth masses, significantly higher than those derived under the optically thin approximation. The resulting disk-to-protostellar mass ratios range from approximately 20–100% in Class 0 disks and about 10–20% in Class I disks. The Toomre Q parameters for these early disks are generally below 2, suggesting that they are likely gravitationally unstable. The inferred dust temperatures are generally higher than those expected from passively heated flared disks, indicating that viscous heating may play a significant role. The maximum grain sizes are estimated based on the derived effective albedo at 1.3 mm and 3.1 mm, which are typically around 100–200 micron in Class 0 disks and larger than 400 micron in Class I disks. In addition, residual images from the radiative transfer modeling suggest the presence of possible faint substructures in some of these early embedded disks.