13C17O suggests gravitational instability in the HL Tau disc [SSA]

http://arxiv.org/abs/2001.07550


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.

Read this paper on arXiv…

A. Booth and J. Ilee
Wed, 22 Jan 20
39/116

Comments: Accepted 2020 January 21. Received 2020 January 21; in original form 2019 November 27