标题： 修订版泰勒-斯普鲁特发电机处方：恒星中的磁性角动量传输 显示英文标题

标题： A Revised Prescription for the Tayler-Spruit Dynamo: Magnetic Angular Momentum Transport in Stars

摘要： 内部磁场的角动量传输是恒星内部模型的重要组成部分。 本文中，我们批判性地检查了Tayler-Spruit发电机模型中的基本启发式假设，该模型描述了如何在差速旋转的恒星辐射区内环形磁场的pinch型不稳定性可能引起大规模流体运动。 我们同意之前发表的工作关于该不稳定的存在的观点，以及其扰动近乎水平的几何形状。 然而，原始Acheson色散关系中的近似仅对小尺度有效，我们不同意该色散关系可以外推到水平尺度接近恒星半径的范围。 我们认为动力学效应，特别是角动量守恒，限制了最大水平尺度。 因此，我们提出了由磁场转矩引起的化学混合和角动量重新分布的传输系数，这些系数与之前发表的值有显著不同。 新的磁粘度比旧的降低了2到3个数量级，我们发现通过此机制的磁场角动量传输对该平均分子量梯度非常敏感。 修订后的系数比之前的系数更符合年轻恒星核心-包层耦合时间尺度的经验约束。 然而，仅包括此机制的太阳模型具有快速旋转的核心，这与日震数据相矛盾。 显示英文摘要

摘要： Angular momentum transport by internal magnetic fields is an important ingredient for stellar interior models. In this paper we critically examine the basic heuristic assumptions in the model of the Tayler-Spruit dynamo, which describes how a pinch-type instability of a toroidal magnetic field in differentially rotating stellar radiative zones may result in large-scale fluid motion. We agree with prior published work both on the existence of the instability and its nearly horizontal geometry for perturbations. However, the approximations in the original Acheson dispersion relation are valid only for small length scales, and we disagree that the dispersion relation can be extrapolated to horizontal length scales of order the radius of the star. We contend that dynamical effects, in particular angular momentum conservation, limit the maximum horizontal length scale. We therefore present transport coefficients for chemical mixing and angular momentum redistribution by magnetic torques that are significantly different from previous published values. The new magnetic viscosity is reduced by 2 to 3 orders of magnitude compared to the old one, and we find that magnetic angular momentum transport by this mechanism is very sensitive to gradients in the mean molecular weight. The revised coefficients are more compatible with empirical constraints on the timescale of core-envelope coupling in young stars than the previous ones. However, solar models including only this mechanism possess a rapidly rotating core, in contradiction with helioseismic data. (abridged)