Evidence for Non-zero Turbulence in the Protoplanetary disc around IM Lup

2024/06/11 by Kevin Flaherty, A. Meredith Hughes, Flaherty, Kevin +15 · 3 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies

paper · pdf · doi:10.48550/arxiv.2406.07689

openalex publication_date 2024/06/11 · openalex created_date 2024/06/15 · openalex updated_date 2026/07/28

Abstract

The amount of turbulence in protoplanetary discs around young stars is critical for determining the efficiency, timeline, and outcomes of planet formation. It is also difficult to measure. Observations are still limited, but direct measurements of the non-thermal, turbulent gas motion are possible with the Atacama Large Millimeter/submillimeter Array (ALMA). Using CO(2-1)/¹³CO(2-1)/C¹⁸O(2-1) ALMA observations of the disc around IM Lup at ~0.4" (~60 au) resolution we find evidence of significant turbulence, at the level of δv_{\rm turb}=(0.18-0.30)c_s. This result is robust against systematic uncertainties (e.g., amplitude flux calibration, midplane gas temperature, disc self-gravity). We find that gravito-turbulence as the source of the gas motion is unlikely based on the lack of an imprint on the rotation curve from a massive disc, while magneto-rotational instabilities and hydrodynamic instabilities are still possible, depending on the unknown magnetic field strength and the cooling timescale in the outer disc.

Cited by

• DiskMINT: Self-Consistent Thermochemical Disk Models with Radially Varying Gas and Dust -- Application to the Massive, CO-Rich Disk of IM Lup
• Understanding JWST water spectra: what can thermochemical models tell us about the (cold) water in protoplanetary disks?
• exoALMA. XVI. Predicting Signatures of Large-scale Turbulence in Protoplanetary Disks

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