Global magnetic patterns in the Milky Way and the Andromeda nebula
Global magnetic patterns in the Milky Way and the Andromeda nebula
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DOI：
10.1093/mnras/264.2.285
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发表时间：
1993-09
影响因子：
4.8
通讯作者：
A. Poezd;A. Shukurov;D. Sokoloff
中科院分区：
文献类型：
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作者：
A. Poezd;A. Shukurov;D. Sokoloff
提出了一种基于α猝灭的非线性薄盘星系发电机模型。假定平均螺旋度取决于圆盘上平均的磁场强度，我们得到了径向发电机方程中非线性的普遍形式。我们将我们的模型应用于银河系和仙女座星云，以研究规则磁场沿半径方向的反转的起源，并获得对磁离子层几何形状和厚度的限制。反转被证明是从种子场结构继承而来的遗迹，如果发电机足够强大，种子场可以存活下来。对于中等厚度的磁离子层h，发电机效率随半层厚度h的增加而增加。
A non-linear, thin-disc galactic dynamo model based on α-quenching is proposed. Assuming that the mean helicity depends on the magnetic field strength averaged across the disc, we derive a universal form of non-linearity in the radial dynamo equation. We apply our model to the Milky Way and the Andromeda nebula to study the origin of reversals, along the radius, of the regular magnetic field, and to obtain constraints on the geometrical shape and thickness of the magnetoionic layer. The reversals are shown to be a relic inherited from the structure of the seed field, which can survive provided that the dynamo is strong enough. The dynamo efficiency increases with the half-thickness of the magnetoionic layer, h, for moderate values of the latter