标题： 具有显著表面环形磁场的恒星发电机模型 显示英文标题

标题： Stellar dynamo models with prominent surface toroidal fields

摘要： 对类似太阳的恒星进行的近期光谱极化观测显示了存在具有主导环向分量的光球磁场。 如果假设外部场为无电流场，则无法在标准平均场发电机理论的框架内解释这些观测结果。 在这项工作中将会展示，如果假设这些恒星的日冕场为调和场，那么潜在的恒星发电机机制可以在轴对称磁拓扑结构存在的条件下支持具有显著环向分量的光球磁场。 特别是，提出日冕中环向能量在低质量快速旋转恒星中的观测增加可以通过潜在的$\alpha\Omega$机制得到自然解释。 显示英文摘要

摘要： Recent spectro-polarimetric observations of solar-type stars have shown the presence of photospheric magnetic fields with a predominant toroidal component. If the external field is assumed to be current-free it is impossible to explain these observations within the framework of standard mean-field dynamo theory. In this work it will be shown that if the coronal field of these stars is assumed to be harmonic, the underlying stellar dynamo mechanism can support photospheric magnetic fields with a prominent toroidal component even in the presence of axisymmetric magnetic topologies. In particular it is argued that the observed increase in the toroidal energy in low mass fast rotating stars can be naturally explained with an underlying $\alpha\Omega$ mechanism.