论文标题
通过直接电流驱动的爆炸事件,理论和观察性证据表明冠状磁场中科里奥利的作用
Theoretical and Observational Evidence for Coriolis Effects in Coronal Magnetic Fields Via Direct Current Driven Flaring Events
论文作者
论文摘要
所有恒星都会产生爆炸性的表面事件,例如耀斑和冠状质量弹出。这些事件是由存储在冠状发电机产生的冠状磁场中的能量驱动的。但是,尚不清楚磁场中的能量沉积是由直流或交替电流驱动的。最近,我们介绍了$ \ sim10^5 $ stars的耀斑强度分布的观察测量值,该样品在$ \ textit {tess} $观察到的主要序列中,所有这些样品都表现出类似于在太阳下观察到的幂律分布,尽管斜坡各不相同。在这里,我们研究了通过直接电流能量沉积产生这种耀斑事件所需的机制,其中冠状磁场编织,重新连接和产生耀斑所需的机制。我们为此过程采用拓扑模型,该过程产生了能量耀斑事件的幂律分布。我们将此模型扩展到包括科里奥利效应,我们证明,恒星中的耀斑能量的分布更迅速(对应于增加耀斑能量的发生率较弱的发生率较弱)。我们提供了观察结果中预测的旋转驱动-LAW指数相关性的暂定证据。我们主张将来对恒星耀斑的观察,这些耀斑将改善我们对幂律指数的测量,并对基于自相似的耀斑强度分布的基本发电机机制产生关键见解。
All stars produce explosive surface events such as flares and coronal mass ejections. These events are driven by the release of energy stored in coronal magnetic fields, generated by the stellar dynamo. However, it remains unclear if the energy deposition in the magnetic fields is driven by direct or alternating currents. Recently, we presented observational measurements of the flare intensity distributions for a sample of $\sim10^5$ stars across the main sequence observed by $\textit{TESS}$, all of which exhibited power-law distributions similar to those observed in the Sun, albeit with varying slopes. Here we investigate the mechanisms required to produce such a distribution of flaring events via direct current energy deposition, in which coronal magnetic fields braid, reconnect, and produce flares. We adopt a topological model for this process which produces a power-law distribution of energetic flaring events. We expand this model to include the Coriolis effect, which we demonstrate produces a shallower distribution of flare energies in stars that rotate more rapidly (corresponding to a weaker decline in occurrence rates toward increasing flare energies). We present tentative evidence for the predicted rotation-power-law index correlation in the observations. We advocate for future observations of stellar flares that would improve our measurements of the power-law exponents, and yield key insights into the underlying dynamo mechanisms that underpin the self-similar flare intensity distributions.