Context. While planet formation is thought to occur early in the history of a protoplanetary disk, the presence of planets embedded in disks, or of other processes driving disk evolution, might be traced from their imprints on the disk structure.
Aims: We study the morphology of the disk around the T Tauri star HD 143006, located in the 5-11 Myr-old Upper Sco region, and we look for signatures of the mechanisms driving its evolution.
Methods: We observed HD 143006 in polarized scattered light with VLT/SPHERE at near-infrared (J-band, 1.2 μm) wavelengths, reaching an angular resolution of 0.037'' ( 6 au). We obtained two datasets, one with a 145 mas diameter coronagraph, and the other without, enabling us to probe the disk structure down to an angular separation of 0.06'' ( 10 au).
Results: In our observations, the disk of HD 143006 is clearly resolved up to 0.5'' and shows a clear large-scale asymmetry with the eastern side brighter than the western side. We detect a number of additional features, including two gaps and a ring. The ring shows an overbrightness at a position angle (PA) of 140°, extending over a range in position angle of 60°, and two narrow dark regions. The two narrow dark lanes and the overall large-scale asymmetry are indicative of shadowing effects, likely due to a misaligned inner disk. We demonstrate the remarkable resemblance between the scattered light image of HD 143006 and a model prediction of a warped disk due to an inclined binary companion. The warped disk model, based on the hydrodynamic simulations combined with three-dimensional radiative transfer calculations, reproduces all major morphological features. However, it does not account for the observed overbrightness at PA 140°.
Conclusions: Shadows have been detected in several protoplanetary disks, suggesting that misalignment in disks is not uncommon. However, the origin of the misalignment is not clear. As-yet-undetected stellar or massive planetary companions could be responsible for them, and naturally account for the presence of depleted inner cavities.
Astronomy and Astrophysics
- Pub Date:
- November 2018
- protoplanetary disks;
- techniques: polarimetric;
- radiative transfer;
- Astrophysics - Earth and Planetary Astrophysics
- Accepted for publication in A&