Oral Presentation

Resolving the inner circumstellar disk in the AB Aurigae system

Author(s): Ya-Wen Tang (ASIAA)

Presenter: Ya-Wen Tang (ASIAA)

We report the analysis of new ALMA observations at 1.3 mm and the archival 2 mm data of the circumstellar disk around the Herbig Ae star AB Aurigae.
The continuum emission at 1.3 mm and the $^{12}$CO 2-1 emission are clear detected and resolved at an angular resolution of 0$\farcs$07 and 0$\farcs$1, respectively.
The continuum emission exhibits a central compact component and and east-west extended component.
The compact component appears associated with a very small inner disk with a radius smaller than 10 au and an unresolved free-free jet and.
Both the CO and the extended dust emissions are brighter on the western side.
The dust emission exhibits an inner spot peaking at the same position at both 2mm and 1.3 mm wavelengths (within the errorbars), at about 15 au from the central star.
Interestingly, the western CO spiral originates from this spot, suggesting that this continuum feature traces a circumplanetary disk.
There is no continuum detection with the upper limit at 1.3 mm wavelength of 0.048 mK at the location of the previously reported planet AB Aurb \citep{Currie+2022}.
The bright spot at radius 30 au, seen both by SPHERE \citep{Boccaletti+2020} at infrared and in the CO spirals \citep{Tang+2017} is not detected in the continuum emission and appears to be linked to an inhomogeneity in the CO distribution.
The SO emission reported by \cite{Dutrey2024} has a location consistent with the western CO spiral and the putative circumplanetary disk, although the angular resolution of the SO data is low.
Our new results demonstrate the complexity to detect young embedded planets in the cavity of gas-rich disks, and it requires several tracers and observational epochs to claim a firm detection.