Details

Autor(en) / Beteiligte

• Lodato, G.
• Rice, W. K. M.

Titel

Testing the locality of transport in self-gravitating accretion discs

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2004-06, Vol.351 (2), p.630-642

Ort / Verlag

Oxford, UK: Blackwell Science Ltd

Erscheinungsjahr

2004

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• In this paper, we examine the issue of characterizing the transport associated with gravitational instabilities in relatively cold discs, discussing in particular the conditions under which it can be described within a local, viscous framework. We present the results of global, three-dimensional, smoothed particle hydrodynamics simulations of self-gravitating accretion discs, in which the disc is cooled using a simple parametrization for the cooling function. Our simulations show that the disc settles in a ‘self-regulated’ state, where the axisymmetric stability parameter Q≈ 1 and where transport and energy dissipation are dominated by self-gravity. We have computed the gravitational stress tensor and compared our results with expectations based on a local theory of transport. We find that, as long as the disc mass is smaller than 0.25M★ and the aspect ratio H/R≲ 0.1, transport is determined locally, thus allowing for a viscous treatment of the disc evolution.