Magneto-driven Shock Waves in Core-Collapse Supernovae
Magneto-driven Shock Waves in Core-Collapse Supernovae
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DOI：
10.1086/424993
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发表时间：
2004-08
期刊：
影响因子：
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通讯作者：
T. Takiwaki;K. Kotake;S. Nagataki;Katsuhiko Sato
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文献类型：
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作者：
T. Takiwaki;K. Kotake;S. Nagataki;Katsuhiko Sato
我们对磁化大质量恒星的旋转核心塌缩进行了一系列二维磁流体动力学模拟。我们采用现实的状态方程，并通过所谓的泄漏方案考虑中微子冷却。在这项研究中，我们系统地研究了强磁场和快速旋转如何影响冲击波的传播。我们的结果表明，在初始极向磁场较强的情况下，通过差动旋转放大的环形磁场变得足够强，足以沿旋转轴产生紧密准直的冲击波。另一方面，在初始磁场较弱的情况下，虽然差速旋转在较长的旋转周期内放大了环形磁场，但发射的冲击波较弱且形状变宽。前一种情况预计会伴随着所谓磁星的形成。我们的模型具有快速旋转和强磁场，可以创建由准直冲击波形成的喷嘴。这可能与塌陷星的情况类似，塌陷星可能是伽马射线暴的中心引擎。
We perform a series of two-dimensional magnetohydrodynamic simulations of the rotational core collapse of a magnetized massive star. We employ a realistic equation of state and take into account the neutrino cooling by the so-called leakage scheme. In this study we systematically investigate how the strong magnetic field and the rapid rotation affect the propagation of the shock waves. Our results show that in the case of the strong initial poloidal magnetic field, the toroidal magnetic field amplified by the differential rotation becomes strong enough to generate a tightly collimated shock wave along the rotational axis. On the other hand, in the case of the weak initial magnetic field, although the differential rotation amplifies the toroidal magnetic field over the long rotational period, the launched shock wave is weak and the shape of it becomes wider. The former case is expected to be accompanied by the formation of the so-called magnetar. Our models with rapid rotation and strong magnetic field can create a nozzle formed by the collimated shock wave. This might be the analogous situation to the collapsar that is plausible as the central engine of the gamma-ray bursts.