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This content will become publicly available on February 21, 2026

Title: Early Grain Growth in the Young Protostellar Disk HH 212 Supported by Dust Self-scattering Modeling
Abstract Grain growth in disks around young stars plays a crucial role in the formation of planets. Early grain growth has been suggested in the HH 212 protostellar disk by previous polarization observations. To confirm it and to determine the grain size, we analyze high-resolution multiband observations of the disk obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) in bands 9 (0.4 mm), 7 (0.9 mm), 6 (1.3 mm), and 3 (3 mm), as well as with the Very Large Array (VLA) in bandKa(9 mm), and we present new VLA data in bandsQ(7 mm),K(1.3 cm), andX(3 cm). We adopt a parameterized flared disk model to fit the continuum maps of the disk in these bands and derive the opacities, albedos, and opacity spectral indexβof the dust in the disk, taking into account the dust scattering ignored in the previous work modeling the multiband data of this source. For the VLA bands, we only include the bandQdata in our modeling to avoid free–free emission contamination. The obtained opacities, albedos, and opacity spectral indexβ(with a value of  ∼1.2) suggest that the upper limit of maximum grain size in the disk should be  ∼130μm, consistent with that implied in the previous polarization observations in band 7, supporting the grain growth in this disk. The values of the absorption opacities further highlight the need for a new dust composition model for Class 0/I disks.  more » « less
Award ID(s):
2307199
PAR ID:
10608969
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
American Astronomical Society
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
981
Issue:
1
ISSN:
0004-637X
Page Range / eLocation ID:
12
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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