The role of the drag force in the gravitational stability of dusty planet-forming disc II. Numerical simulations
Articolo
Data di Pubblicazione:
2023
Citazione:
The role of the drag force in the gravitational stability of dusty planet-forming disc II. Numerical simulations / C. Longarini, P. J Armitage, G. Lodato, D. J Price, S. Ceppi. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 1365-2966. - 522:4(2023), pp. 6217-6235. [10.1093/mnras/stad1400]
Abstract:
Young protostellar discs are likely to be both self-gravitating, and to support grain growth to sizes where the particles decoupled
from the gas. This combination could lead to short-wavelength fragmentation of the solid component in otherwise non-
fragmenting gas discs, forming Earth-mass solid cores during the Class 0/I stages of young stellar object evolution. We use
three-dimensional smoothed particle hydrodynamics simulations of two-fluid discs, in the regime where the Stokes number of the
particles St > 1, to study how the formation of solid clumps depends on the disc-to-star mass ratio, the strength of gravitational
instability, and the Stokes number. Gravitational instability of the simulated discs is sustained by local cooling. We find that the
ability of the spiral structures to concentrate solids increases with the cooling time and decreases with the Stokes number, while
the relative dynamical temperature between gas and dust of the particles decreases with the cooling time and the disc-to-star
mass ratio and increases with the Stokes number. Dust collapse occurs in a subset of high disc mass simulations, yielding clumps
whose mass is close to linear theory estimates, namely 1–10 M⊕. Our results suggest that if planet formation occurs via this
mechanism, the best conditions correspond to near the end of the self-gravitating phase, when the cooling time is long and the
Stokes number close to unity.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
accretion, accretion discs; protoplanetary discs; turbulence
Elenco autori:
C. Longarini, P. J Armitage, G. Lodato, D. J Price, S. Ceppi
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