Invited Presentation
Planet Formation in AB Aurigae: Imaging of the Inner Gaseous Spirals inside the dust cavity
Presenter: Ya-Wen Tang (ASIAA)
We report high angular resolution (0.1") observations with ALMA of the 1.3 mm
continuum and 12CO J=2-1 emission from the inner 100 AU of the disk surrounding the Herbig Ae star AB Aurigae. The continuum emission shows three distinct feature: a compact (~ 2 au) dust disk around the star, the asymmetric dust ring at 120 AU, and previously undetected
extended emission about 30 AU around the star along the rotation axis of the
system. The CO emission is dominated by two prominent spiral-like arms. After correction for the large scale flux resolved out by these observations, these arms appear to be about twice brighter than their surrounding medium. Their kinematics is consistent with Keplerian rotation at an inclination of 30 degree.
The apparent two arm spiral pattern is best explained by tidal disturbances
created by an unseen companion located at 60--80 au, with dust confined in the pressure bumps created outside this companion orbit. However, the residual continuum emission, coinciding with the peak CO brightness and a large pitch angle of the spiral at this location, suggests another hidden object here, which would help to explain the overall emptiness of the cavity.
asiaa.sinica.edu.tw