Data di Pubblicazione:
2011
Citazione:
Stability of self-gravitating discs under irradiation / W. K. M. Rice, P. J. Armitage, G. R. Mamatsashvili, G. Lodato, C. J. Clarke. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 0035-8711. - 418:2(2011), pp. 1356-1362.
Abstract:
Self-gravity becomes competitive as an angular momentum transport process in accretion discs at large radii, where the temperature is low enough that external irradiation likely contributes to the thermal balance. Irradiation is known to weaken the strength of disc self-gravity, and can suppress it entirely if the disc is maintained above the threshold for linear instability. However, its impact on the susceptibility of the disc to fragmentation is less clear. We use two-dimensional numerical simulations to investigate the evolution of self-gravitating discs as a function of the local cooling time and strength of irradiation. In the regime where the disc does not fragment, we show that local thermal equilibrium continues to determine the stress – which can be represented as an effective viscous α– out to very long cooling times, (at least 240 dynamical times). In this regime, it is also found that the power spectrum of the perturbations is uniquely set by this effective viscous α and not by the cooling rate. Fragmentation occurs for cooling times tau
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Accretion, accretion discs; Galaxies: active; Hydrodynamics; Protoplanetary discs; Stars: formation
Elenco autori:
W. K. M. Rice, P. J. Armitage, G. R. Mamatsashvili, G. Lodato, C. J. Clarke
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