The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure
The vertical distribution of dust in debris disks is sensitive to the number and size of large planetesimals dynamically stirring the disk, and is therefore well-suited for constraining the prevalence of otherwise unobservable Uranus and Neptune analogs. Information regarding stirring bodies has pre...
| Main Authors: | , , , , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
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American Astronomical Society
2020
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| Online Access: | https://hdl.handle.net/1721.1/124914 |
| _version_ | 1826189887681855488 |
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| author | Daley, Cail Hughes, A. Meredith Carter, Evan S. Flaherty, Kevin Lambros, Zachary Margaret, Pan Schlichting, Hilke Chiang, Eugene Wyatt, Mark Wilner, David Andrews, Sean Carpenter, John |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Daley, Cail Hughes, A. Meredith Carter, Evan S. Flaherty, Kevin Lambros, Zachary Margaret, Pan Schlichting, Hilke Chiang, Eugene Wyatt, Mark Wilner, David Andrews, Sean Carpenter, John |
| author_sort | Daley, Cail |
| collection | MIT |
| description | The vertical distribution of dust in debris disks is sensitive to the number and size of large planetesimals dynamically stirring the disk, and is therefore well-suited for constraining the prevalence of otherwise unobservable Uranus and Neptune analogs. Information regarding stirring bodies has previously been inferred from infrared and optical observations of debris disk vertical structure, but theoretical works predict that the small particles traced by short-wavelength observations will be puffed up by radiation pressure, yielding only upper limits. The large grains that dominate the disk emission at millimeter wavelengths are much less sensitive to the effects of stellar radiation or stellar winds, and therefore trace the underlying mass distribution more directly. Here we present ALMA 1.3 mm dust continuum observations of the debris disk around the nearby M star AU Mic. The 3 au spatial resolution of the observations, combined with the favorable edge-on geometry of the system, allows us to measure the vertical thickness of the disk. We report a scale height-to-radius aspect ratio of = -h 0.031+0.004 0.005 between radii of ∼23 au and ∼41 au. Comparing this aspect ratio to a theoretical model of size-dependent velocity distributions in the collisional cascade, we find that the perturbing bodies embedded in the local disk must be larger than about 400 km, and the largest perturbing body must be smaller than roughly 1.8M. These measurements rule out the presence of a gas giant or Neptune analog near the ∼40 au outer edge of the debris ring, but are suggestive of large planetesimals or an Earth-sized planet stirring the dust distribution. Key words: circumstellar matter; planet–disk interactions; planetary systems; stars: individual (AU Mic);
submillimeter: planetary systems |
| first_indexed | 2024-09-23T08:27:33Z |
| format | Article |
| id | mit-1721.1/124914 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:27:33Z |
| publishDate | 2020 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | mit-1721.1/1249142022-09-30T09:20:45Z The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure Daley, Cail Hughes, A. Meredith Carter, Evan S. Flaherty, Kevin Lambros, Zachary Margaret, Pan Schlichting, Hilke Chiang, Eugene Wyatt, Mark Wilner, David Andrews, Sean Carpenter, John Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences The vertical distribution of dust in debris disks is sensitive to the number and size of large planetesimals dynamically stirring the disk, and is therefore well-suited for constraining the prevalence of otherwise unobservable Uranus and Neptune analogs. Information regarding stirring bodies has previously been inferred from infrared and optical observations of debris disk vertical structure, but theoretical works predict that the small particles traced by short-wavelength observations will be puffed up by radiation pressure, yielding only upper limits. The large grains that dominate the disk emission at millimeter wavelengths are much less sensitive to the effects of stellar radiation or stellar winds, and therefore trace the underlying mass distribution more directly. Here we present ALMA 1.3 mm dust continuum observations of the debris disk around the nearby M star AU Mic. The 3 au spatial resolution of the observations, combined with the favorable edge-on geometry of the system, allows us to measure the vertical thickness of the disk. We report a scale height-to-radius aspect ratio of = -h 0.031+0.004 0.005 between radii of ∼23 au and ∼41 au. Comparing this aspect ratio to a theoretical model of size-dependent velocity distributions in the collisional cascade, we find that the perturbing bodies embedded in the local disk must be larger than about 400 km, and the largest perturbing body must be smaller than roughly 1.8M. These measurements rule out the presence of a gas giant or Neptune analog near the ∼40 au outer edge of the debris ring, but are suggestive of large planetesimals or an Earth-sized planet stirring the dust distribution. Key words: circumstellar matter; planet–disk interactions; planetary systems; stars: individual (AU Mic); submillimeter: planetary systems United States. National Aeronautics and Space Administration (Grant NNX15AM35G) United States. National Aeronautics and Space Administration (Grant NNX15AK23G) 2020-04-28T20:42:48Z 2020-04-28T20:42:48Z 2019-04 2019-03 2020-04-13T15:28:27Z Article http://purl.org/eprint/type/JournalArticle 1538-4357 0004-637X https://hdl.handle.net/1721.1/124914 Daley, Cail, et al. “The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure.” The Astrophysical Journal 875, 2 (April 2019): 87. © 2019 The American Astronomical Society en http://dx.doi.org/10.3847/1538-4357/AB1074 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Astronomical Society The American Astronomical Society |
| spellingShingle | Daley, Cail Hughes, A. Meredith Carter, Evan S. Flaherty, Kevin Lambros, Zachary Margaret, Pan Schlichting, Hilke Chiang, Eugene Wyatt, Mark Wilner, David Andrews, Sean Carpenter, John The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure |
| title | The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure |
| title_full | The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure |
| title_fullStr | The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure |
| title_full_unstemmed | The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure |
| title_short | The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure |
| title_sort | mass of stirring bodies in the au mic debris disk inferred from resolved vertical structure |
| url | https://hdl.handle.net/1721.1/124914 |
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