The gravitational instability in the dust layer of a protoplanetary disk:. axisymmetric solutions for nonuniform dust density distributions in the direction vertical to the midplane
The gravitational instability in the dust layer of a protoplanetary disk:. axisymmetric solutions for nonuniform dust density distributions in the direction vertical to the midplane
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原行星盘尘埃层中的重力不稳定：。
DOI：
10.1016/j.icarus.2004.03.002
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发表时间：
2004
期刊：
影响因子：
3.2
通讯作者：
M. Sekiya
中科院分区：
文献类型：
--
作者：
Fumiharu Yamoto;M. Sekiya
研究了垂直于中平面方向尘埃密度分布不均匀的原行星盘尘埃层的引力不稳定性。对重力不稳定性进行了线性分析。(1)采用一种流体模型，即忽略尘埃与气体之间的速度差。(2)气体不可压缩。(3)模型相对于圆盘的旋转轴是轴对称的。数值结果表明，在中间平面处的临界密度高于Sekiya (1983, Prog。定理。物理学报，69,1116-1130)。对于高斯粉尘密度分布，临界密度高1.3倍，尽管由于粉尘层中的剪切不稳定，我们认为这种粉尘密度分布不现实。对于理查德森数恒定的粉尘密度分布，认为是由于剪切失稳而实现的，其临界密度高2.85倍，且与理查德森数的值无关。此外，如果理查德森数可以降低到0.001量级，那么即使尘埃与气体表面密度比随太阳丰度的增加也会实现引力不稳定性。我们的结果给出了引力不稳定性对星子形成的一个新的限制。
The gravitational instability in the dust layer of a protoplanetary disk with nonuniform dust density distributions in the direction vertical to the midplane is investigated. The linear analysis of the gravitational instability is performed. The following assumptions are used: (1) One fluid model is adopted, that is, difference of velocities between dust and gas are neglected. (2) The gas is incompressible. (3) Models are axisymmetric with respect to the rotation axis of the disk. Numerical results show that the critical density at the midplane is higher than the one for the uniform dust density distribution by Sekiya (1983, Prog. Theor. Phys. 69, 1116–1130). For the Gaussian dust density distribution, the critical density is 1.3 times higher, although we do not consider this dust density distribution to be realistic because of the shear instability in the dust layer. For the dust density distribution with a constant Richardson number, which is considered to be realized due to the shear instability, the critical density is 2.85 times higher and is independent of the value of the Richardson number. Further, if a constant Richardson number could decrease to the order of 0.001, the gravitational instability would be realized even for the dust to gas surface density ratio with the solar abundance. Our results give a new restriction on planetesimal formation by the gravitational instability.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell