ALMA Band 6 high-resolution observations of the transitional disk around SY Chamaeleontis
Abstract
In this study, we reported the results of high-resolution (${0{^{\prime \prime}_{.}}14}$) Atacama Large Millimeter/submillimeter Array (ALMA) observations of the 225 GHz dust continuum and CO molecular emission lines from the transitional disk around SY Cha. Our high-resolution observations clearly revealed the inner cavity and the central point source for the first time. The radial profile of the ring can be approximated by a bright narrow ring superimposed on a fainter wide ring. Furthermore, we found that there is a weak azimuthal asymmetry in dust continuum emission. For gas emissions, we detected 12CO(2-1), 13CO(2-1), and C18O(2-1), from which we estimated the total gas mass of the disk to be 2.2 × 10-4 M ⊙ , assuming a CO/H2 ratio of 10-4. The observations showed that the gas is present inside the dust cavity. The analysis of the velocity structure of the 12CO(2-1) emission line revealed that the velocity is distorted at the location of the dust inner disk, which may be owing to a warping of the disk or radial gas flow within the cavity of the dust disk. High-resolution observations of SY Cha showed that this system is composed of a ring and a distorted inner disk, which may be common, as indicated by the survey of transitional disk systems at a resolution of ${\sim}{0{^{\prime \prime}_{.}}1}$.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- April 2023
- DOI:
- 10.1093/pasj/psad009
- arXiv:
- arXiv:2302.05659
- Bibcode:
- 2023PASJ...75..424O
- Keywords:
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- protoplanetary disks;
- stars: individual (SY Chamaeleontis);
- stars: pre-main sequence;
- submillimeter: planetary systems;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 33 pages, 22 figures