Galloway-Sprietsma, M, Bae, J, Teague, R et al. (19 more authors) (2023) Molecules with ALMA at Planet-forming Scales (MAPS): Complex Kinematics in the AS 209 Disk Induced by a Forming Planet and Disk Winds. The Astrophysical Journal, 950 (2). 147. ISSN 0004-637X
Abstract
We study the kinematics of the AS 209 disk using the J = 2–1 transitions of 12CO, 13CO, and C18O. We derive the radial, azimuthal, and vertical velocity of the gas, taking into account the lowered emission surface near the annular gap at ≃1farcs7 (200 au) within which a candidate circumplanetary-disk-hosting planet has been reported previously. In 12CO and 13CO, we find a coherent upward flow arising from the gap. The upward gas flow is as fast as 150 m s−1 in the regions traced by 12CO emission, which corresponds to about 50% of the local sound speed or 6% of the local Keplerian speed. Such an upward gas flow is difficult to reconcile with an embedded planet alone. Instead, we propose that magnetically driven winds via ambipolar diffusion are triggered by the low gas density within the planet-carved gap, dominating the kinematics of the gap region. We estimate the ambipolar Elsässer number, Am, using the HCO+ column density as a proxy for ion density and find that Am is ∼0.1 at the radial location of the upward flow. This value is broadly consistent with the value at which numerical simulations find that ambipolar diffusion drives strong winds. We hypothesize that the activation of magnetically driven winds in a planet-carved gap can control the growth of the embedded planet. We provide a scaling relationship that describes the wind-regulated terminal mass: adopting parameters relevant to 100 au from a solar-mass star, we find that the wind-regulated terminal mass is about one Jupiter mass, which may help explain the dearth of directly imaged super-Jovian-mass planets.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
Keywords: | Planet formation; Protoplanetary disks; Radio interferometry |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Funding Information: | Funder Grant number STFC (Science and Technology Facilities Council) ST/X001016/1 STFC (Science and Technology Facilities Council) ST/T000287/1 MRC (Medical Research Council) MR/T040726/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 18 Jul 2023 15:19 |
Last Modified: | 22 Aug 2023 10:35 |
Published Version: | http://dx.doi.org/10.3847/1538-4357/accae4 |
Status: | Published |
Publisher: | IOP |
Identification Number: | 10.3847/1538-4357/accae4 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:200836 |
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Licence: CC-BY 4.0