Global gravitational instabilities in discs with infall Global GIs in discs with infall
Global gravitational instabilities in discs with infall Global GIs in discs with infall
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内陷盘中的全球重力不稳定性 内陷盘中的全球 GI
DOI：
10.1111/j.1365-2966.2010.18146.x
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发表时间：
2011
影响因子：
4.8
通讯作者：
Harsono D
中科院分区：
文献类型：
--
作者：
Harsono D
引力不稳定性在驱动大质量原恒星盘中的气体吸积中起着重要作用。特别强的是全球引力不稳定性，当盘质量是中心星星质量的0.1量级，并且具有比盘的垂直尺度高度大得多的特征空间尺度时，这种不稳定性就会出现。在本文中，我们使用三维数值流体力学研究的发展，在一个磁盘中的引力不稳定性是嵌入在一个致密的，气体的信封。我们发现，全球引力不稳定性的角动量输运的光盘与下落的主导模式，在其他相同的孤立的光盘。吸积力矩所产生的低阶，全球模式的引力不稳定性在一个磁盘受到下降是一个大的几个因素比一个孤立的磁盘相同的质量。我们表明，这种全球性的引力不稳定性是由强大的垂直剪切之间的接口盘和信封，并建议，这一过程可能是一个重要的手段，驾驶吸积年轻的恒星。
Gravitational instability plays an important role in driving gas accretion in massive protostellar discs. Particularly strong is the global gravitational instability which arises when the disc mass is of order 0.1 of the mass of the central star and has a characteristic spatial scale much greater than the disc's vertical scaleheight. In this paper we use three-dimensional numerical hydrodynamics to study the development of gravitational instabilities in a disc which is embedded in a dense, gaseous envelope. We find that global gravitational instabilities are the dominant mode of angular momentum transport in the disc with infall, in contrast to otherwise identical isolated discs. The accretion torques created by low-order, global modes of the gravitational instability in a disc subject to infall are larger by a factor of several than an isolated disc of the same mass. We show that this global gravitational instability is driven by the strong vertical shear at the interface between the disc and the envelope, and suggest that this process may be an important means of driving accretion on to young stars.