Quasi-Periodic Pulsations in Solar and Stellar Flares: A Review of Underpinning Physical Mechanisms and Their Predicted Observational Signatures
Quasi-Periodic Pulsations in Solar and Stellar Flares: A Review of Underpinning Physical Mechanisms and Their Predicted Observational Signatures
复制标题
DOI：
10.1007/s11214-021-00840-9
复制
发表时间：
2021-07
影响因子：
10.3
通讯作者：
I. Zimovets;J. McLaughlin;A. Srivastava;D. Kolotkov;A. Kuznetsov;E. Kupriyanova;I. Cho;A. Inglis-A.-Ingli
中科院分区：
文献类型：
--
作者：
I. Zimovets;J. McLaughlin;A. Srivastava;D. Kolotkov;A. Kuznetsov;E. Kupriyanova;I. Cho;A. Inglis-A.-Ingli
太阳耀斑和恒星耀斑中的准周期脉动（QPP）现象已经被发现50多年了，在这一研究领域已经取得了重大进展。很明显，QPP并不罕见，它们在许多耀斑中被发现，因此，强大的耀斑模型应该以自然的方式再现它们的特性。至少有15种机制/模型已经被开发来解释太阳耀斑中的QPP，这些机制/模型主要假设日冕结构（磁环和电流片）中存在磁流体动力学（MHD）振荡或磁重联的准周期机制。我们回顾了最重要和最有趣的耀斑QPP的结果，强调近年来的结果，我们提出的预测和突出的观测签名的15个机制。然而，由于大多数模型的性质是定性的，而不是定量的，并且由于耀斑区域的物理特性，特别是QPP源的空间结构的观测信息不足，因此还不可能得出关于正确的QPP机制的明确结论。我们还回顾了恒星耀斑中的QPP，其中的进展主要是基于太阳-恒星类比，这表明太阳和磁活性恒星耀斑区域的物理过程具有相似性。在太阳和恒星耀斑中存在具有类似性质的QPP，本身就是一个强有力的支持太阳-恒星类比可能性的额外论据。因此，提高我们对太阳耀斑中的QPP的理解，为了解恒星耀斑提供了一个重要的额外信息渠道。然而，需要在理论/模拟和观测方面做进一步的工作。
The phenomenon of quasi-periodic pulsations (QPPs) in solar and stellar flares has been known for over 50 years and significant progress has been made in this research area. It has become clear that QPPs are not rare—they are found in many flares and, therefore, robust flare models should reproduce their properties in a natural way. At least fifteen mechanisms/models have been developed to explain QPPs in solar flares, which mainly assume the presence of magnetohydrodynamic (MHD) oscillations in coronal structures (magnetic loops and current sheets) or quasi-periodic regimes of magnetic reconnection. We review the most important and interesting results on flare QPPs, with an emphasis on the results of recent years, and we present the predicted and prominent observational signatures of each of the fifteen mechanisms. However, it is not yet possible to draw an unambiguous conclusion as to the correct underlying QPP mechanism because of the qualitative, rather than quantitative, nature of most of the models and also due to insufficient observational information on the physical properties of the flare region, in particular the spatial structure of the QPP source. We also review QPPs in stellar flares, where progress is largely based on solar-stellar analogies, suggesting similarities in the physical processes in flare regions on the Sun and magnetoactive stars. The presence of QPPs with similar properties in solar and stellar flares is, in itself, a strong additional argument in favor of the likelihood of solar-stellar analogies. Hence, advancing our understanding of QPPs in solar flares provides an important additional channel of information about stellar flares. However, further work in both theory/simulations and in observations is needed.