COSMIC RADIATION AND COSMIC MAGNETIC FIELDS .2. ORIGIN OF COSMIC MAGNETIC FIELDS
COSMIC RADIATION AND COSMIC MAGNETIC FIELDS .2. ORIGIN OF COSMIC MAGNETIC FIELDS
复制标题
DOI：
10.1103/physrev.82.863
复制
发表时间：
1951-01-01
期刊：
影响因子：
--
通讯作者：
SCHLUTER, A
中科院分区：
文献类型：
--
作者：
BIERMANN, L;SCHLUTER, A
给出了控制全部或部分电离气体在磁场作用下运动的方程。强调在许多实际情况下，电导率与磁场强度无关。考虑了气态物体非刚性转动产生的磁场的定常情况。这样的场是环型的。极向场可能是由磁化的星际物质向恒星收缩产生的。考虑了湍流导电物质(恒星或星际物质)中磁场强度的增加。得出的结论是，每个量级的湍流最终都会产生一个磁场，其能量密度大致对应于所考虑的湍流的能量密度。如果开始时磁场较弱，这种状态首先是通过最小尺度和最小速度的湍流达到的，然后是由更高阶的湍流达到的，因此，只要这个过程继续下去，磁场强度就必须长期变化。如果我们的星系在其早期阶段只有弱场，那么现在的磁场应该对应于与103光年量级(在10−6到10−5 Gauss之间)距离相关的湍流速度，并且这些场在这个数量级的距离上应该或多或少是均匀的。如果开始时已经有了场，现在的场可能会更强一些。
The equations governing the behavior of a wholly or partly ionized gas moving in the presence of a magnetic field are given. It is emphasized that the electric conductivity is independent of the magnetic field strength in many cases of actual interest. The stationary case of a magnetic field arising from the nonrigid rotation of a gaseous body is considered. Such a field is of the toroidal type. Fields of poloidal type may arise by the contraction of magnetized interstellar matter towards a star. The increase of strength of a magnetic field in turbulent conducting matter (stellar or interstellar) is considered. The conclusion is reached that the turbulence of every order of magnitude leads finally to a magnetic field, the energy density of which corresponds roughly to the energy density of the turbulence considered. If the magnetic field was weak in the beginning, this state was reached at first by the turbulence of smallest scale and smallest velocity, and then by the turbulence of higher orders; hence, the magnetic field strength must change secularly, as long as this process goes on. If our galaxy had only weak fields in its earlier stages, the present magnetic field should correspond to the turbulent velocity associated with distances of the order of 10 3 light years (between 10− 6 and 10− 5 gauss), and these fields should be more or less homogeneous over distances of this order. If there were already fields in the beginning, the present fields might be somewhat stronger.