Magnetic confinement of dense plasma inside (and outside) stellar coronae
Magnetic confinement of dense plasma inside (and outside) stellar coronae
复制标题
星冕内部（和外部）致密等离子体的磁约束
DOI：
10.1093/mnras/stac1698
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发表时间：
2022
影响因子：
4.8
通讯作者：
Waugh R
中科院分区：
文献类型：
--
作者：
Waugh R
在高质量和低质量恒星的磁层中都发现了致密等离子体的磁约束。被捕获的物质追踪磁场结构，通常在距离星星很远的地方，那里的磁场结构很难观察到。这项工作特别关注快速旋转的类太阳恒星，这种行为以“弹弓”的形式被很好地观察到。我们已经产生了一个模型，用于产生与一系列日冕磁场平衡的冷却磁回路。这些环可以用来填充模型日冕和限制物质在恒星表面以上的高度范围很广。我们计算的质量为弹弓双折射的星星AB剑鱼座，与观测值一致。该模型产生两种类型的解决方案：在低高度和高大的解决方案超出了共同旋转半径的高峰回路。我们发现，低洼的解决方案是沉重的足迹，一般遵循的背景场的形状。我们称之为类太阳辐射。高的解决方案是首脑会议沉重，并离心支持。这些是弹弓的子弹。在封闭的日冕之外的恒星风中可以找到这些高的解。Hα尾迹是为具有一系列场几何形状和日冕范围的各种日冕场结构生成的。类似的Hα尾迹是由一系列的全局场结构产生的，这意味着物质的磁约束在快速旋转的恒星中应该是常见的。
Magnetic confinement of dense plasma is found in the magnetospheres of both high- and low-mass stars. Trapped material traces the magnetic field structure, often at large distances from the star where the magnetic structure is otherwise difficult to observe. This work looks specifically at rapidly rotating, solar-like stars where this behaviour is well observed in the form of ‘slingshot’ prominences. We have produced a model for generating cooled magnetic loops in equilibrium with a range of coronal magnetic fields. These loops can be used to populate model coronae and confine material at a wide range of heights above the stellar surface. We calculate masses for slingshot prominences for the star AB Doradus that are consistent with observational values. The model produces two types of solution: loops with summits at low heights and tall solutions beyond the co-rotation radius. We show that the low-lying solutions are footpoint heavy and generally follow the shape of the background field. We refer to these as solar-like prominences. The tall solutions are summit heavy and are centrifugally supported. These are are the slingshot prominences. These tall solutions can be found within the stellar wind, beyond the closed corona. Hαtrails are generated for various coronal field structures with a range of field geometries and coronal extents. Similar Hαtrails are produced by a range of global field structures, which implies that magnetic confinement of material should be common in rapidly rotating stars.