Walsh, C orcid.org/0000-0001-6078-786X, Daley, C, Facchini, S et al. (1 more author) (2017) CO emission tracing a warp or radial flow within ≲100 au in the HD 100546 protoplanetary disk. Astronomy and Astrophysics, 607. A114. ISSN 0004-6361
Abstract
We present spatially resolved Atacama Large Millimeter/submillimeter Array (ALMA) images of 12CO J = 3−2 emission from the protoplanetary disk around the Herbig Ae star, HD 100546. We expand upon earlier analyses of this data and model the spatially-resolved kinematic structure of the CO emission. Assuming a velocity profile which prescribes a flat or flared emitting surface in Keplerian rotation, we uncover significant residuals with a peak of ≈7δv, where δv = 0.21 km s-1 is the width of a single spectral resolution element. The shape and extent of the residuals reveal the possible presence of a severely warped and twisted inner disk extending to at most 100 au. Adapting the model to include a misaligned inner gas disk with (i) an inclination almost edge-on to the line of sight, and (ii) a position angle almost orthogonal to that of the outer disk reduces the residuals to <3δv. However, these findings are contrasted by recent VLT/SPHERE, MagAO/GPI, and VLTI/PIONIER observations of HD 100546 that show no evidence of a severely misaligned inner dust disk down to spatial scales of ~ 1 au. An alternative explanation for the observed kinematics are fast radial flows mediated by (proto)planets. Inclusion of a radial velocity component at close to free-fall speeds and inwards of ≈50 au results in residuals of ≈4δv. Hence, the model including a radial velocity component only does not reproduce the data as well as that including a twisted and misaligned inner gas disk. Molecular emission data at a higher spatial resolution (of order 10 au) are required to further constrain the kinematics within ≲100 au. HD 100546 joins several other protoplanetary disks for which high spectral resolution molecular emission shows that the gas velocity structure cannot be described by a purely Keplerian velocity profile with a universal inclination and position angle. Regardless of the process, the most likely cause is the presence of an unseen planetary companion.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © ESO 2017. Reproduced with permission from Astronomy & Astrophysics. |
Keywords: | Protoplanetary disks; Planet-disk interactions; Submillimeter: planetary systems; Stars: individual: HS 100546 |
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) |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Dec 2017 10:43 |
Last Modified: | 05 Dec 2017 10:43 |
Published Version: | https://www.aanda.org/articles/aa/abs/2017/11/aa31... |
Status: | Published |
Publisher: | EDP Sciences |
Identification Number: | 10.1051/0004-6361/201731334 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:124788 |