AI 中文总结
该研究分析了2024年11月6日X2.3级耀斑相关的高频II型射电暴，发现无大尺度白光CME时紧凑磁通量绳爆发仍可产生低日冕激波并生成该射电暴。
AI 中文摘要
射电观测是太阳日冕的有力诊断工具，可用于研究与太阳耀斑、日冕物质抛射（CME）及激波相关的动力学现象。我们对2024年11月6日发生的X2.3级太阳耀斑相关的罕见高频II型射电暴进行了多波段分析，该射电暴起始频率约为750 MHz，频率漂移率约为0.5 MHz s⁻¹。SDO/AIA视场在耀斑开始后不久观测到传播的极紫外（EUV）扰动，而射电频谱仪在世界时13:46至13:56期间记录到该II型射电暴，频率范围约为750至45 MHz。南赛射电日像仪（NRH）的射电成像观测显示，射电源在事件期间向南传播。Aditya-L1卫星上的HEL1OS的X射线光谱分析及太阳轨道器上的STIX成像观测揭示了与耀斑相关的有效非热电子加速的迹象。非线性无力场（NLFFF）外推法在源区识别出一个爆发前的磁通量绳，而事件期间获得的白光日冕仪观测未发现可检测的大尺度CME。通过立体EUV观测推导的爆发磁通量绳速度，在测量不确定度范围内与从射电动态频谱推断出的激波速度一致。这些观测共同表明，即使在没有可检测的白光CME的情况下，紧凑磁通量绳爆发也能产生低日冕激波，进而生成高频II型射电辐射。
英文摘要
Radio observations provide a powerful diagnostic of the solar corona, enabling investigations of dynamic phenomena associated with solar flares, coronal mass ejections (CMEs), and shock waves. We present a multiwavelength analysis of a rare high-frequency type II radio burst (starting frequency of $\sim$750 MHz and frequency drift rate of $\sim$0.5 MHz s$^{-1}$) associated with the X2.3-class solar flare that occurred on 6 November 2024. A propagating EUV disturbance was observed shortly after the flare onset in the SDO/AIA field of view, while radio spectrographs recorded the type II burst between 13:46 and 13:56 UT over a frequency range of $\sim$750 to 45 MHz. Radio imaging observations from the Nançay Radioheliograph (NRH) show that the radio sources propagate southward during the event. X-ray spectroscopy from HEL1OS onboard Aditya-L1 and imaging observations from STIX onboard Solar Orbiter reveal signatures of efficient non-thermal electron acceleration associated with the flare. An NLFFF extrapolation identifies a pre-eruptive magnetic flux rope in the source region, while white-light coronagraph observations obtained during the event show no detectable large-scale CME. The speed of the erupting flux rope, derived from stereoscopic EUV observations, is consistent, within measurement uncertainties, with the shock speed inferred from the radio dynamic spectrum. Together, these observations suggest that compact flux rope eruptions, even in the absence of a detectable white-light CME, can generate low-coronal shocks capable of producing high-frequency type II radio emission.
CommentsAccepted for publication in The Astrophysical Journal, 18 Pages, 8 Figures, 1 Table
