Fedele, D, Carney, M, Hogerheijde, MR et al. (6 more authors) (2017) ALMA unveils rings and gaps in the protoplanetary system HD 169142: signatures of two giant protoplanets. Astronomy & Astrophysics, 600. A72. ISSN 0004-6361
Abstract
The protoplanetary system HD 169142 is one of the few cases where a potential candidate protoplanet has recently been detected by direct imaging in the near-infrared. To study the interaction between the protoplanet and the disk itself, observations of the gas and dust surface density structure are needed. This paper reports new ALMA observations of the dust continuum at 1.3 mm, 12CO, 13CO, and C18O J = 2−1 emission from the system HD 169142 (which is observed almost face-on) at an angular resolution of ∼0.3"×0.2′′ (∼35 × 20 au). The dust continuum emission reveals a double-ring structure with an inner ring between 0.17"−0.28" (∼20−35 au) and an outer ring between 0.48−0.64 (∼56−83 au). The size and position of the inner ring is in good agreement with previous polarimetric observations in the near-infrared and is consistent with dust trapping by a massive planet. No dust emission is detected inside the inner dust cavity (R <~ 20 au) or within the dust gap (∼35−56 au) down to the noise level. In contrast, the channel maps of the J = 2−1 line of the three CO isotopologs reveal gas inside the dust cavity and dust gap. The gaseous disk is also much larger than the compact dust emission; it extends to ∼1.5" (∼180au) in radius. This difference and the sharp drop of the continuum emission at large radii point to radial drift of large dust grains (>μm size). Using the thermo-chemical disk code dali, we modeled the continuum and the CO isotopolog emission to quantitatively measure the gas and dust surface densities. The resulting gas surface density is reduced by a factor of ∼30−40 inward of the dust gap. The gas and dust distribution indicate that two giant planets shape the disk structure through dynamical clearing (dust cavity and gap) and dust trapping (double-ring dust distribution).
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © ESO 2017. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | stars:variables: T Tauri, Herbig AeBe; protoplanetary disks; planet-disk interactions |
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: | 04 Apr 2017 10:58 |
Last Modified: | 04 Apr 2017 10:58 |
Published Version: | http://www.aanda.org/articles/aa/abs/2017/04/aa298... |
Status: | Published |
Identification Number: | 10.1051/0004-6361/201629860 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:114518 |