A Model of Astrophysical Tori with Magnetic Fields
A Model of Astrophysical Tori with Magnetic Fields
复制标题
具有磁场的天体物理环面模型
DOI：
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发表时间：
1989
影响因子：
2.3
通讯作者：
R. Matsumoto
中科院分区：
文献类型：
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作者：
Rika Okada;J. Fukue;R. Matsumoto
在全空间比角动量恒定、磁场只有环向分量的假设下，建立了稳态轴对称的磁流体环模型。此外，假定气体是多变的，并且假设磁场以某种特定的方式用密度的幂和半径的幂来表示。利用伪牛顿势模拟了相对论效应。结果表明，由于远离对称轴的磁场占据主导地位，具有环形磁场的环面沿对称轴方向拉长。此外，尽管漏斗的形状和尖端的位置没有改变，但与没有磁场的情况相比，密度最大的底部位置接近中心。为了这种磁流体环面的存在，比角动量和底部的Alfven速度等参数的取值被限制在一定的范围内。
A steady axisymmetric model of magnetohydrodynamical tori is con structed under the assumptions that the specific angular momentum is constant in whole space and the magnetic field has only the toroidal component. Furthermore, the gas is assumed to be polytropic and the magnetic field is supposed to be expressed by a power of the density"and the radius in some specified manner. The relativistic effect is simulated by use of a pseudo-Newtonian potential. It is found that the configuration of the torus with a toroidal magnetic field is elongated along the symmetry axis because of the dominance by the magnetic field far from the axis. Furthermore, the position of the bottom where the density is maximum approaches the center in comparison with the case without magnetic field, although the shape of the funnel and the location of the cusp do not change. In order for such MHD tori to exist, the values of the parameters, e.g., the specific angular momentum and the Alfven speed at the bottom are restricted in some ranges.