Supercloud formation by nonaxisymmetric gravitational instabilities in sheared magnetic galaxy disks
Supercloud formation by nonaxisymmetric gravitational instabilities in sheared magnetic galaxy disks
复制标题
剪切磁星系盘中非轴对称引力不稳定性导致的超级云形成
DOI：
10.1086/164907
复制
发表时间：
1987
期刊：
影响因子：
--
通讯作者：
B. Elmegreen
中科院分区：
文献类型：
--
作者：
B. Elmegreen
研究了气体圆盘中剪切扰动的引力稳定性。考虑了初始扰动的实际形状和振幅。磁场使各种密度的气体都不稳定。坍塌主要沿着平均场方向进行，对于压力平衡场强，其增长率与非旋转、非磁性的Jeans不稳定性相似。正常盘状星系的周围星际介质应该在1亿年的时间尺度上自发地形成低密度、1000万太阳质量的云复体。
The gravitational stability of sheared perturbations in magnetic gas disks is investigated. Realistic shapes and amplitudes for the initial perturbations are considered. The magnetic field destabilizes the gas for all densities. The collapse is primarily along the mean field direction, and for a pressure-equilibrium field strength, the growth rate is similar to that for the nonrotating, nonmagnetic Jeans instability. The ambient interstellar medium in normal disk galaxies should spontaneously form low-density, 10 million solar mass cloud complexes on time scales of 100 million yr. 84 references.