1989年1月18日白光耀斑的研究

Studies of White-Light Flare on Jan. 18, 1989

本文利用色球Ｈα单色光序列照相资料、Ｈα光谱扫描资料、黑子精细结构照相资料和日面纵向磁场观测资料，分析了１９８９年１月１８日ＷＬＦ所在活动区ＮＯＡＡ／ＵＳＡＦ：５３１２的磁场结构、黑子结构及该ＷＬＦ的演化特征，求出了视向速度场，并以理论计算的Ｈα谱线轮廓作为诊断工具，探讨了该ＷＬＦ可能的能量传输机制和动力学过程，得出如下结论：①活动区光球黑子结构复杂，磁场位形为δ结构。白光核位于磁中性线上或其附近，出现在黑子本影与半影的交界处、半影上、半影与光球交界处或光球背景上。ＷＬＦ出现前，色球暗条均被激活并迅速消失。周围纤维形成有序排列。该ＷＬＦ同谱斑密切相关，但只有在被激活、迅速消失的小暗条附近，同时又爆发过小耀斑或受小耀斑影响的谱斑，才有可能引发ＷＬＦ。②该ＷＬＦ有７个亮核，大小为（１．５～４）＊１０１７ｃｍ２，寿命从几分钟到长达４０ｍｉｎ以上。对比强度Ｃ在Ｈα接近１０％，在Ｈγ可达２０％。③该ＷＬＦ的视向速度场较复杂，各白光核都位于ＶＨ＝０线附近，存在红、蓝两种位移，但ＶＨ数值很小，一般在±１０ｋｍｓ－１之间。④除有线心反转外，各白光核处的Ｈα轮廓基本对称。有些核只有较弱的吸收型Ｈα轮廓；有些核的Ｈα发射宽而?

In the present thesis, based onanalysing the synchronous filtergrams, two dimensional Hα spectra, quasi-synchronous photographs of sunspot and magnetograms of the active rgion NOAA / USAF: 5312 with a WLF appeared on January 18, 1989, we have studied the structures of sunspots, magnetic field of the active region and the time evolution of the WLF, and obtained the corresponding line-of-sight velocity field. Using the calculated line profiles as a diagnostic means, we disscussed the energy transport mechanisms and dynamical processes. The main conclusions are as follows: ①In active region NOAA 5312, the structure of the photospheric sunspot is complicated, the configuration of the magnetic field is of the δ-structure. Several main WL kernels lie at or near the magnetic neutral line, they originated at the juncture of umbra and penumbra and the juncture of penumbra and photosphere in penumbra or on the photosphere background.Before WLF appeared, chromospheric filaments were activated and disappeared rapidly,the fibrils in the place would be arranged in order. The WLF associated with plages tightly, but only the plages near some small activated, then disappeared filaments, and associated with subflares would probably induce WLF.②The WLF consists of seven kernels with a dimension of around (1.5～4) * 1017cm2, and the life time of these kernels range from several minutes to more than 40 minutes. The contrast intensities of contimuum emissions are around 10% for Ha and up to 20% for Hγ, respectively.③The velocity field of the WLF is also complicated, every WL kernel is near VH =0 line with both small red and blue shifts ranging from-10 kms-1 to +10 kms-1. ④The Hα line profiles from these WL kernel sites are nearly symmetric except the central reversal. The profiles from some kernels are of absorption type and not intense, and the others are broad, intense and self-reversed with different red and blue peak intensities. ⑤It seems that high energy proton beam bombardment and dynamical energy transport by a chromospheric condensation are not important in this event. Some WL kernels probably originate from photosphere, and some WL kernels are probably caused by nonthermal electron beam bombardment. Finally, we have noticed that the present WLF might be an intermediate one which possesses both type Ⅰ and type Ⅱ WLF natures.