On the edge: Assessing the structure of protoplanetary disks from a unique perspective
Abstract
The physical structure of protoplanetary disks both sets the stage for, and is strongly affected by, planet formation. A full understanding of that process therefore requires a detailed characterization of the radial and vertical structure of the gas-rich disks associated with young pre-main sequence stars. Of particular interest are disks observed edge-on, as they provide the ideal configuration to unambiguously disentangle the radial and vertical dimensions. Here we present HST and ALMA high resolution imaging (up to a few AU scales) of three edge-on disks in the nearby Taurus and Ophiuchus star-forming regions. The combination of scattered light images, millimeter continuum images and CO emission maps enable a robust comparison of the spatial distribution of the micron-sized dust grains, millimeter-size grains and gas in each of these disks. We find that the large dust grains are constrained to a remarkably flat subdisk as a consequence of dust settling. We place stringent constraint on the thickness of this subdisk in each system. Furthermore, this subdisk is markedly more compact radially than both the small dust and gas components, confirming the prediction of dust radial migration. We also present compelling evidence that the millimeter continuum emission is strongly optically thick in at least one system. Finally, we find the gas component to extend even further out (by up to a factor of 2) than the small dust component, suggesting either a dust-poor outer region or that the outer reaches of disks are shielded from the central starlight.
- Publication:
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American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23331706D