Modeling magnetically channeled winds in 3D: I. isothermal simulations of a magnetic O supergiant
Modeling magnetically channeled winds in 3D: I. isothermal simulations of a magnetic O supergiant
复制标题
以 3D 方式模拟磁引导风：I. 磁 O 超巨星的等温模拟
DOI：
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发表时间：
2022
影响因子：
4.8
通讯作者：
M. Gagne
中科院分区：
文献类型：
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作者：
Sethupathy S.;D. Balsara;A. ud;M. Gagne
在本文中，我们提出了第一组三维磁流体力学（MHD）模拟执行的Riemann Geomesh代码。我们研究磁性大质量恒星的磁性通道风的动力学在全三维使用的代码，是唯一适合于球形问题。具体地说，我们对一颗旋转恒星上的平滑风进行了等温模拟，该恒星最初具有倾斜的偶极场。我们比较了质量损失，角动量损失，和模板星的磁层动力学（与O4超巨星ζ Pup的性质类似）在一定范围内的旋转速率，磁场强度，和磁倾斜角度。模拟运行到准稳态，观察到的结果与现有文献一致，显示了质量流出的间歇性离心爆发事件，受到形成恒星封闭磁层的磁环的限制。编目结果提供了在不同转速、磁场强度和大磁倾斜角度下角动量损失如何变化的视角。与之前的二维MHD研究一致，我们发现高磁约束降低了整体的质量损失率，而更高的旋转增加了质量损失率。这项研究和未来的研究将用于估计磁性大质量恒星的角动量演变，自旋下降时间和质量损失演变作为磁场强度，旋转速率和偶极子倾斜的函数。
In this paper we present the first set of 3D magnetohydrodynamic (MHD) simulations performed with the Riemann Geomesh code. We study the dynamics of the magnetically channeled winds of magnetic massive stars in full three dimensions using a code that is uniquely suited to spherical problems. Specifically, we perform isothermal simulations of a smooth wind on a rotating star with a tilted, initially dipolar field. We compare the mass-loss, angular momentum loss, and magnetospheric dynamics of a template star (with the properties that are reminiscent of the O4 supergiant ζ Pup) over a range of rotation rates, magnetic field strengths, and magnetic tilt angles. The simulations are run up to a quasi-steady state and the results are observed to be consistent with the existing literature, showing the episodic centrifugal breakout events of the mass outflow, confined by the magnetic field loops that form the closed magnetosphere of the star. The catalogued results provide perspective on how angular-momentum loss varies for different configurations of rotation rate, magnetic field strength and large magnetic tilt angles. In agreement with previous 2D MHD studies, we find that high magnetic confinement reduces the overall mass-loss rate, and higher rotation increases the mass-loss rate. This and future studies will be used to estimate the angular-momentum evolution, spin-down time, and mass-loss evolution of magnetic massive stars as a function of magnetic field strength, rotation rate, and dipole tilt.