2022/03/03 by Francesco Zagaria, C. J. Clarke, Cathie J. Clarke +4 · 20 citations
Chemistry · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Molecular Spectroscopy and Structure #Multiplicity (mathematics) #Physics #Population #Star formation #Stars #Stellar mass #Stellar population #Stellar, planetary, and galactic studies #Young stellar object #astro-ph.EP #astro-ph.GA #astro-ph.SR
paper · pdf · open access · doi:10.1093/mnras/stac621
published in Monthly Notices of the Royal Astronomical Society 512(3), 3538-3550 (Oxford University Press) · 13 pages, 6 figures; accepted for publication in MNRAS
arxiv created 2022/03/03 · openalex publication_date 2022/03/04 · arxiv updated 2022/03/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In recent years a correlation between mass accretion rates onto new-born stars and their proto-planetary disc masses was detected in nearby young star-forming regions. Although such a correlation can be interpreted as due to viscous-diffusion processes in the disc, highly-accreting sources with low disc masses in more evolved regions remain puzzling. In this paper, we hypothesise that the presence of a stellar companion truncating the disc can explain these outliers. Firstly, we searched the literature for information on stellar multiplicity in Lupus, Chamaeleon~I and Upper Sco, finding that roughly 20 per cent of the discs involved in the correlation are in binaries or higher-order multiple stellar systems. We prove with high statistical significance that at any disc mass these sources have systematically higher accretion rates than those in single-stars, with the bulk of the binary population being clustered around Mdisc/Macc≈0.1 Myr. We then run coupled gas and dust one-dimensional evolutionary models of tidally truncated discs to be compared with the data. We find that these models are able to reproduce well most of the population of observed discs in Lupus and Upper Sco, even though the unknown eccentricity of each binary prevents an object by object comparison. In the latter region, the agreement improves if the grain coagulation efficiency is reduced, as may be expected in discs around close binaries. Finally, we mention that thermal winds and sub-structures can be important in explaining few outlying sources.