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arXiv · 2001.07550

13C17O suggests gravitational instability in the HL Tau disc

Alice S. Booth·John D. Ilee
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Abstract

We present the first detection of the 13C17O J=3-2 transition toward the HL Tau protoplanetary disc. We find significantly more gas mass (at least a factor of ten higher) than has been previously reported using C18O emission. This brings the observed total disc mass to 0.2 M, which we consider to be a conservative lower limit. Our analysis of the Toomre Q profile suggests that this brings the disc into the regime of gravitational instability. The radial region of instability (50-110 au) coincides with the location of a proposed planet-carved gap in the dust disc and a spiral in the gas. We, therefore, propose that if the origin of the gap is confirmed to be due to a forming giant planet, then it is likely to have formed via the gravitational fragmentation of the protoplanetary disc.

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Alice S. Booth, John D. Ilee. 2020-01-21. 13C17O suggests gravitational instability in the HL Tau disc. https://doi.org/10.1093/mnrasl%2Fslaa014

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