发表机构
School of Astronomy and Space Science, Nanjing University; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education; Institute of Frontier and Interdisciplinary Science, Shandong University; Institute of Space Sciences, Shandong University（南京大学天文与空间科学学院; 教育部现代天文与天体物理重点实验室（南京大学）; 山东大学前沿交叉科学研究中心; 山东大学空间科学研究院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究结合 FAST 和 TESS 观测，在 M 矮星 EQ Peg 的超耀斑期间探测到精细结构射电爆发，其高亮温和高偏振表明源于电子回旋脉泽，为超耀斑起源提供证据。
AI 中文摘要
超耀斑经常在磁活动恒星上被观测到，尤其是在活跃的 M 矮星上，从而影响附近系外行星的宜居性。然而，超耀斑的成因仍不清楚。在此，我们结合 FAST 和 TESS，于 2022 年 9 月 8 日在 M 矮星双星 EQ Peg 上的一次白光超耀斑（总热辐射能量约为 $10^{33} \rm erg$）期间，探测到一次呈尖峰群形式的精细结构分米波射电爆发。最显著的尖峰出现在光学耀斑峰值时间附近，持续约 $100 \rm s$。这些射电尖峰呈现出极高的亮温（$\gtrsim 10^{13} \rm K$）和高程度的圆偏振（约 $0.84 \pm 0.16$），表明其源于相干辐射过程，极有可能是电子回旋脉泽。基于 EQ Peg 的 Zeeman-Doppler 成像测量，我们进一步在大尺度偶极磁场构型的假设下，定位了射电尖峰的源区，包括其高度和纬度。这些结果为恒星耀斑产生的精细结构分米波射电爆发提供了有力证据，并有助于揭示超耀斑的起源。
英文摘要
Superflares are frequently observed on magnetically active stars, particularly on active M-dwarfs, thereby influencing the habitability of nearby exoplanets. However, the causes of superflares remain unclear. Here, combining FAST and TESS, we detected a finely structured decimetric radio burst appearing as groups of spikes during a white-light superflare (total bolometric energy $\sim 10^{33} \ \mathrm{erg}$) on the M-dwarf binary EQ Peg on September 8th, 2022. The most significant ones appeared near the peak time of the optical flare and lasted for about $100 \ \mathrm{s}$. The radio spikes present extremely high brightness temperatures ($\gtrsim 10^{13} \ \mathrm{K}$) and high degrees of circular polarization ($\sim 0.84 \pm 0.16$), indicating the origin of a coherent emission process, most likely the electron cyclotron maser. Based on Zeeman-Doppler Imaging measurements of EQ Peg, we further locate the sources of the radio spikes, including their heights and latitudes, under the assumption of a large-scale dipolar magnetic field configuration. The results provide strong evidence for finely structured decimetric radio bursts generated by stellar flares and shed light on the origin of superflares.
