ALMA Super-resolution Imaging of T Tau: r = 12 au Gap in the Compact Dust Disk around T Tau N

Abstract

Based on Atacama Large Millimeter/submillimeter Array (ALMA) observations, compact protoplanetary disks with dust radii of r 20 − 40 au were found to be dominant in nearby low-mass star formation regions. However, their substructures have not been investigated because of the limited spatial resolution achieved so far. We apply a newly developed super-resolution imaging technique utilizing sparse modeling (SpM) to explore several au-scale structures in such compact disks. SpM imaging can directly solve for the incomplete sampling of visibilities in the spatial frequency and potentially improve the fidelity and effective spatial resolution of ALMA images. Here, we present the results of the application to the T Tau system. We use the ALMA 1.3 mm continuum data and achieve an effective spatial resolution of ∼ 30% (5 au) compared with the conventional CLEAN beam size at a resolution of 17 au. The reconstructed image reveals a new annular gap structure at r = 12 au in the T Tau N compact disk with a dust radius of 24 au, and resolves the T Tau Sa and Sb binary into two sources. If the observed gap structure in the T Tau N disk is caused by an embedded planet, we estimate a Saturn-mass planet when the viscous parameter of the disk is 10 −3 . Ultimately, ALMA observations with enough angular resolution and sensitivity should be able to verify the consistency of the super-resolution imaging and definitely confirm the existence of this disk substructure.

Stellar multiplicity affects the correlation between proto-planetary disc masses and accretion rates: binaries explain high-accretors in Upper Sco

“…Sub-structures have been detected in binary discs as well: e.g., spirals in HT Lup A and AS 205 N (Kurtovic et al 2018), inner cavities in XZ Tau B (Osorio et al 2016), UZ Tau E and CIDA 9A (Long et al 2019;Manara et al 2019a), gaps and rings in AS 205 S (Kurtovic et al 2018), GQ Lup A (Long et al 2020) and T Tau N (Yamaguchi et al 2021). However, it is not clear if they are as common as in isolated discs.…”

Massive compact dust disk with a gap around CW Tau revealed by ALMA multi-band observations

“…However, the scattering contributes to the intensity as an additional parameter, meaning that analysis with more than four wavelengths is essential to solve the degeneracy between these parameters. Although compact disks are also supposed to have substructures potentially induced by forming-planets as larger population does (e.g., Yamaguchi et al 2021), the multi-wavelength characterization toward compact disks is still sparse due to the limited resolution.…”