Turbulent viscosity in clumpy accretion disks - II. Supernova driven turbulence in the Galaxy
Turbulent viscosity in clumpy accretion disks - II. Supernova driven turbulence in the Galaxy
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块状吸积盘中的湍流粘度 - II。
DOI：
10.1051/0004-6361:20030436
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发表时间：
2003
影响因子：
6.5
通讯作者：
T. Beckert
中科院分区：
文献类型：
--
作者：
Bernd Vollmer;T. Beckert
提出了湍流块状气盘的分析模型，其中湍流由超新星输入的能量维持。盘参数、全局填充因子、分子分数和恒星形成速率的表达式给出为托姆参数 Q 、云大小与湍流驱动长度尺度 δ 之间的比率、盘内质量吸积率 $\dot{M}$、分子形成常数 α 、盘半径、角速度及其径向导数的函数。研究了两种不同的情况：主星盘和 z 方向的自引力气体盘。第一种方法是通过能量通量守恒来确定湍流驱动波长，即超新星能量输入通过湍流传输到较小的尺度并在较小尺度上消散。将结果与全引力模型的结果进行比较。对于 $Q=1$ 和 $\delta=1$ ，两个模型彼此一致。在第二种方法中，驱动长度尺度直接由超新星遗迹的大小决定。两种模型都应用于银河系，并且可以再现其整体和局部气体特性。研究了热压力和磁压力对磁盘结构的影响。我们推断银河系的 $Q \sim 1$ 和 $\dot{M} \sim 0.05$–0.1 $M_{\odot}$ yr -1。
An analytical model for a turbulent clumpy gas disk is presented where turbulence is maintained by the energy input due to supernovae. Expressions for the disk parameters, global filling factors, molecular fractions, and star formation rates are given as functions of the Toomre parameter Q , the ratio between the cloud size and the turbulent driving length scale δ , the mass accretion rate within the disk $\dot{M}$, the constant of molecule formation α , the disk radius, the angular velocity, and its radial derivative. Two different cases are investigated: a dominating stellar disk and a self-gravitating gas disk in z direction. The turbulent driving wavelength is determined in a first approach by energy flux conservation, i.e. the supernovae energy input is transported by turbulence to smaller scales where it is dissipated. The results are compared to those of a fully gravitational model. For $Q=1$ and $\delta=1$ both models are consistent with each other. In a second approach the driving length scale is directly determined by the size of supernovae remnants. Both models are applied to the Galaxy and can reproduce its integrated and local gas properties. The influence of thermal and magnetic pressure on the disk structure is investigated. We infer $Q \sim 1$ and $\dot{M} \sim 0.05$–0.1 $M_{\odot}$ yr -1 for the Galaxy.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell