Dust Rings and Cavities in the Protoplanetary Disks around HD 163296 and DoAr 44

TL;DR

This study models the dust and substructure in the protoplanetary disks around HD 163296 and DoAr 44, revealing dust mass estimates, potential planet masses, and disk formation mechanisms based on multi-wavelength observations.

Contribution

The paper provides detailed models of disk substructures, estimates dust masses, and constrains potential planet masses, advancing understanding of planet formation conditions.

Findings

Dust masses in disks are consistent with previous estimates.

Potential planet mass in DoAr 44's cavity is between 0.5 and 1.6 Jupiter masses.

Disk structures can be explained by dust drift through gas distributions.

Abstract

We model substructure in the protoplanetary disks around DoAr 44 and HD 163296 in order to better understand the conditions under which planets may form. We match archival millimeter-wavelength thermal emission against models of the disks' structure that are in radiation balance with the starlight heating and in vertical hydrostatic equilibrium, and then compare to archival polarized scattered near-infrared images of the disks. The millimeter emission arises in the interior, while the scattered near-infrared radiation probes the disks' outer layers. Our best model of the HD 163296 disk has dust masses $81\pm 13$ $M_\oplus$ in the inner ring at 68 au and $82^{+26}_{-16}$ $M_\oplus$ in the outer ring at 102 au, both falling within the range of estimates from previous studies. Our DoAr 44 model has total dust mass $84^{+7.0}_{-3.5}$ $M_\oplus$. Unlike HD 163296, DoAr 44 as of yet has no detected planets. If the central cavity in the DoAr 44 disk is caused by a planet, the planet's mass must be at least 0.5 $M_J$ and is unlikely to be greater than 1.6 $M_J$. We demonstrate that the DoAr 44 disk's structure with a bright ring offset within a fainter skirt can be formed by dust particles drifting through a plausible distribution of gas.