Gravitational Collapse of Interstellar Magnetized Clouds

星际磁化云的引力塌缩

基本信息

批准号：
07640351
负责人：
TOMISAKA Kohji
金额：
$ 1.41万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640351/
关键词：
Interstellar Clouds Star Formation Interstellar Magnetic Fields Gravitational Collapse Adaptive Method

项目摘要

The evolution of an isothermal magnetized interstellar cloud was studied with a parallelized magnetohydrodynamics (MHD) code and a fast Poisson solver based on the CGS (conjugate gradient squared) method.Since the density distribution of a cloud in the dynamical contraction phase is central-peaked, the code must have fine spatial resolution near the center, while in the outer part numerical grid must be large. The 'nested grid technique' meets these contradictory conditions. A number of grids are prepared ; finer ones cover only the central part, while coarser ones cover the whole cloud.1.From the numerical simulation using the nested grid method, it is shown that (1) a disk is formed perpendicular to the magnetic field lines, and that (2) the disk evolves in a self-similar manner and the solution reaches a special power-law distribution : for example, the density on the equatorial plane indicates a power-law as p (r) * r^<-2>.2.In a finite time, the solution becomes singular. After the epoch, matter begins to accrete onto a central body with a finite mass. This is studied using a sink cell method. (1) From this, it is shown that an outward-facing shock front is formed in the disk in the accretion phase. Infalling matter is stopped at the shock surface and is accelerated again. (2) The mass accretion rate is much larger than the standard rate obtained by Shu.

研究了一个平行的磁性水力动力学（MHD）代码（MHD）代码和基于CGS（共轭梯度平方）方法的快速泊松求解器的磁化云的演变。与动态相关阶段的云的密度分布相比，一定要在整个中心范围内，在动态相关阶段的确定性中，云的密度分布在中心范围内。 “嵌套网格技术”符合这些矛盾的条件。准备了许多网格； finer ones cover only the central part, while coarser ones cover the whole cloud.1.From the numerical simulation using the nested grid method, it is shown that (1) a disk is formed perpendicular to the magnetic field lines, and that (2) the disk evolves in a self-similar manner and the solution reaches a special power-law distribution : for example, the density on the equatorial plane indicates a power-law as p (r) * r^<-2> .2。在有限的时间内，解决方案变得单数。纪元之后，物质开始积聚在有限质量的中央体内。这是使用水槽细胞方法研究的。（1）从中，可以表明在积聚阶段的磁盘中形成了外向冲击锋。插入物质在冲击表面停止，并再次加速。（2）质量积聚率远大于SHU获得的标准率。