FORMATION OF PROTOSTELLAR JETS AS TWO-COMPONENT OUTFLOWS FROM STAR–DISK MAGNETOSPHERES
FORMATION OF PROTOSTELLAR JETS AS TWO-COMPONENT OUTFLOWS FROM STAR–DISK MAGNETOSPHERES
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作为星盘磁层两组分流出的原恒星喷流的形成
DOI：
10.1088/0004-637x/692/1/346
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
C. Fendt
中科院分区：
文献类型：
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作者：
C. Fendt
轴对称磁流体动力学模拟已用于研究（1）中心恒星磁层和恒星风与周围磁化盘流出之间的相互关系，以及（2）大型喷流的整体形成如何受其影响。施加的初始磁场分布是两个分量的叠加——恒星偶极子和周围的盘磁场——平行或反平行排列。相应地，质量流出以恒星风加盘风的形式发射。我们的模拟从具有初始无力磁场配置的流体静力平衡的初始状态演变而来。由于恒星和圆盘之间的差异旋转，会感应出强大的环形磁场分量。恒星偶极子大规模膨胀并张开。恒星风和盘风可能以一对平行的流出物的形式演化。然而，相当强的盘风分量的存在对于准直至关重要。正如之前的数值研究所知，经典的盘式射流由于中央恒星风的压力而变得不太准直。在一些模拟中，我们观察到强烈耀斑的产生会触发流出质量损失率（或速度）突然变化两倍，同时伴随着动量通量和射流上射流速度的径向分布的重新分布。我们讨论这样的假设：这些耀斑可能会引发渐近喷流的内部激波，这些渐近喷流被观察为结。
Axisymmetric magnetohydrodynamic simulations have been applied to investigate (1) the interrelation between a central stellar magnetosphere and stellar wind with a surrounding magnetized disk outflow, and (2) how the overall formation of a large scale jet is affected by that. The initial magnetic field distribution applied is a superposition of two components—the stellar dipole and the surrounding disk magnetic field—in either parallel or antiparallel alignment. Correspondingly, the mass outflow is launched as stellar wind plus disk wind. Our simulations evolve from an initial state in hydrostatic equilibrium with an initially force-free magnetic field configuration. Due to differential rotation between star and disk, a strong toroidal magnetic field component is induced. The stellar dipole inflates and opens up on large scale. Stellar wind and disk wind may evolve in a pair of collimated outflows. However, the existence of a reasonably strong disk wind component is essential for collimation. The classical disk jet, as known from previous numerical studies, becomes less collimated due to the pressure of the central stellar wind. In some simulations we observe the generation of strong flares triggering a sudden change in the outflow mass loss rate (or velocity) by a factor of two, accompanied by a redistribution in the radial profile of momentum flux and jet velocity across the jet. We discuss the hypothesis that these flares may trigger internal shocks in the asymptotic jets which are observed as knots.
吸积盘射流的三维 MHD 模拟，
DOI：
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发表时间：
2005
期刊：
APJ 634
影响因子：
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作者：
Kigure.H.;Shibata.K.
通讯作者：
Shibata.K.