| 太阳爆发事件中磁重联电流片的观测特征研究 |
其他题名 | Observation features research of magnetic reconnection current sheet associated with solar eruption events
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| 蔡强伟
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学位类型 | 硕士
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导师 | 林隽
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| 2015-07-01
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学位授予单位 | 中国科学院研究生院
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学位授予地点 | 北京
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学位专业 | 天体物理
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关键词 | 太阳:日冕物质抛射
太阳:电流片
太阳:辐射测量
太阳:紫外
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摘要 | 本文首先对太阳结构及主要活动现象做简单描述。随后对日冕物质抛射的观测和研究意义,以及磁重联电流片的观测和理论研究给出阐述。然后我们对研究工作进行详细的描述。最后,是对此次工作的总结,以及对未来工作的展望。日冕物质抛射(CME)之后的太阳日冕边缘观测表明,通常能够在日冕边缘观测到强烈的UV源。在这个区域会发生反向磁力线局部耗散引起的重构以及磁能释放的过程(即磁重联),重联区域会有一定程度拉伸,称为重联电流片。磁重联电流片在事件爆发的过程中,既是磁自由能迅速转化为热能、等离子动能和高能粒子束流的重要区域,又起着连接日冕物质抛射和耀斑的作用。我们对2003年1月3日和11月4日的CME事件进行了分析研究。两次事件在CME离开太阳表面附近之后,均有电流片被观测到。我们结合搭载在SOHO上的LASCO、UVCS数据,以及大熊湖天文台和云南天文台的Hα资料,研究两次爆发事件的动力学特征,以及电流片的物理特性。电流片中高电离度粒子的存在,如Fe+17、Si+11,表明电流片区域中温度高达(3~5)×106K。直接测量发现电流片的厚度在1.3×104km~1.1×105km范围之间,并且随时间在逐渐减小。利用CHIANTI(ver 7.1)光谱代码,我们进一步计算得到2003年1月3日电流片中的电子温度和相应辐射量(EM)的平均值分别为3.84×106K和6.1×1024cm-5。另一方面,我们利用SOHO/UVCS观测数据对2003年11月4日的CME爆发事件中的电流片进行分析,发现电流片呈现准周期性扭转运动。 |
其他摘要 | In the paper, we give a brief instruction to the solar structure and main activity phenomenon at first, and then describe observation and research significance of coronal mass ejection, as well as magnetic reconnection current sheet observation and theoretical research. Afterwards, we give a detail description about our work. At last, it is a summary and an indication of the direction for our further work. After coronal mass ejection(CME),off-limb observations of solar coronal indicate existing strong UV source existing at solar coronal region. In this region, it happened reconstruct of antiparallel magnetic filed lines caused by local diffusion and energy release process(i.e. magnetic reconnection). The region stretched by eruption is so-called reconnection current sheet. In the CME event eruption process, CS not only be the important region where magnetic free energy quickly convert into thermal, kinetic energy and high energy particle beam, but also be the ”bridge” of connecting CME and flare. We analyze the CME events happened in 2003 January 3 and November 4. After coronal mass ejection leaving solar surface, both event observed the formation of CS . We combine the data from the Large Angle and Spectrometric Coronagraph Experiment, Ultraviolet Coronagraph Spectrometer on board the Solar and Heliospheric Observatory, as well as from the Big Bear Solar Observatory and Yunnan Observatories H images, to investigate the dynamical properties of these two events, and physical properties of the current sheets. The existence of highly ionized particles, such asFe+17, Si+11, indicate in the current sheet the temperature reached up to (3-5)* 10^6 K. The width of CSs in two events is about 1.3 * 10^4 km -- 1.1 * 10^5 km, decreasing with time. Using CHIANTI(ver 7.1), we can further calculate the electron temperature and emission measure of the CS in the 2003 January 3 event, and obtain the mean value of 3.84 * 10^6 K and 6.1 * 10^24 cm^(?5) respectively. For the 2003 November 4 event, we calculate the velocity difference between current sheet two sides, finding that wings of the CS show quasi-periodic twist motion. |
学科领域 | 天文学
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语种 | 中文
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文献类型 | 学位论文
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条目标识符 | http://ir.ynao.ac.cn/handle/114a53/9464
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专题 | 太阳物理研究组
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作者单位 | 中国科学院云南天文台
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推荐引用方式 GB/T 7714 |
蔡强伟. 太阳爆发事件中磁重联电流片的观测特征研究[D]. 北京. 中国科学院研究生院,2015.
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