MHD disc winds can reproduce fast disc dispersal and the correlation between accretion rate and disc mass in Lupus
journal contributionposted on 2022-04-12, 09:56 authored by B Tabone, GP Rosotti, G Lodato, PJ Armitage, AJ Cridland, EF van Dishoeck
Abstract The final architecture of planetary systems depends on the extraction of angular momentum and mass-loss processes of the discs in which they form. Theoretical studies proposed that magnetized winds launched from the discs (MHD disc winds) could govern accretion and disc dispersal. In this work, we revisit the observed disc demographics in the framework of MHD disc winds, combining analytical solutions of disc evolution and a disc population synthesis approach. We show that MHD disc winds alone can account for both disc dispersal and accretion properties. The decline of disc fraction over time is reproduced by assuming that the initial accretion timescale (a generalization of the viscous timescale) varies from disc to disc and that the decline of the magnetic field strength is slower than that of the gas. The correlation between accretion rate and disc mass, and the dispersion of the data around the mean trend as observed in Lupus is then naturally reproduced. The model also accounts for the rapidity of the disc dispersal. This paves the way for planet formation models in the paradigm of wind-driven accretion.
BT acknowledges support from the research programme Dutch Astrochemistry Network II with project number 614.001.751, which is (partly) financed by the Dutch Research Council (NWO). GR acknowledges support from the Netherlands Organisation for Scientific Research (NWO; programme number 016.Veni.192.233) and from an STFC Ernest Rutherford Fellowship (grant number ST/T003855/1). This work is also funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 325594231, FOR 2634/2. We are grateful to C. F. Manara for sharing the Lupus data.
CitationMonthly Notices of the Royal Astronomical Society: Letters, Volume 512, Issue 1, May 2022, Pages L74–L79, https://doi.org/10.1093/mnrasl/slab124
Author affiliationDepartment of Physics and Astronomy, University of Leicester
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