太阳Ⅱ型射电暴精细结构的观测研究  

Recent Observational Studies on the Fine Structures of Solar Type Ⅱ Radio Bursts

作　　者：冯士伟 吕茂水 FENG Shi-wei;LV Mao-shui(Institute of Space Sciences,Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment,School of Space Science and Physics,Shandong University,Weihai 264209,China)

机构地区：[1]山东大学空间科学与物理学院,山东省光学天文与日地空间环境重点实验室,空间科学研究院,威海264209

出　　处：《天文学进展》2021年第2期129-143,共15页Progress In Astronomy

基　　金：国家自然科学基金委员会-中国科学院天文联合基金项目(U1831101)。

摘　　要：在太阳射电动态频谱图上,Ⅱ型暴表现为缓慢频率漂移的窄带信号;这些信号为能量电子激发的等离子体辐射,其基频辐射的频率接近当地等离子体频率。Ⅱ型暴在太阳暴驱动激波、激波加速产生能量电子以及空间天气预报方面具有重要的研究意义。有些Ⅱ型暴的频谱形态比较丰富,存在多种精细结构;按照频谱形态和成因大致分为频带分裂、多支、鱼骨状以及骤变Ⅱ型暴。这些精细结构可用于诊断电子数密度、磁场强度等日冕参数和确定相关激波的速度、位形等,以及更深入地理解太阳暴过程。然而,Ⅱ型暴精细结构的成因仍存在很多问题,需要进一步研究,特别地,需要利用我国新建设备的高分辨率数据开展研究。Ⅱ型暴精细结构的观测研究进展以及需要关注的问题将在文中做详细论述。In the solar radio dynamic spectrum,type Ⅱ radio bursts appear as narrow-band features drifting slowly from higher to lower frequency.These signals are due to plasma radiation excited by energetic electrons.For fundamental plasma radiation,the emission is close to the local plasma frequency.Type Ⅱ bursts provide important insights in the studies of shock waves driven by solar eruptions,shock-accelerated energetic electrons and space weather forecasting.In addition,type Ⅱ radio bursts have a variety of fine structures in the dynamic spectrum.According to their spectrotemporal features,they can be roughly categorized into type Ⅱ radio bursts with band-splitting,multi-branch,herringbone,and sudden-spectral change structures.These fine structures can be used to diagnose coronal parameters such as electron density and magnetic field strength,to determine the speed and configuration of the associated shock waves,and to further understand the solar eruption processes.However,there are still many unresolved problems in the cause of these fine structures,which require further research.In particular,it is of great importance to use data with high angular resolution available from newly-built radio heliographs in China for research.This article reviews recent progresses on observational studies of the fine structures of type Ⅱ radio bursts and outlines outstanding issues for future studies.

关 键 词：太阳物理 太阳电磁辐射 太阳射电辐射 太阳日冕物质抛射激波 

分 类 号：P182[天文地球—天文学]