耀斑日冕硬X射线源观测研究

对于足点被日面边缘遮挡住的耀斑的观测研究是诊断日冕硬X射线辐射的一个重要方法.通过统计分析RHESSI (Reuven Ramaty High-Energy Solar Spectroscopic Imager)卫星观测到的71个此类耀斑硬X射线源发现,前人提出的两类源,即日冕X射线辐射中热辐射与非热辐射源区空间分离较小的源和分离较大的源,在能谱、成像、光变曲线以及GOES持续时间等方面都没有显著的区别,其中辐射区的面积、耀斑总热能以及GOES持续时间与分离距离之间有很好的相关性.这些结果支持近年来提出的一些耀斑统一模型.同时也表明Masuda耀斑只是一类非常特殊的事件,不具有日冕硬X射线辐射的一般特征.     

太阳10cm波爆发与共生的硬X射线耀斑中精细结构的分析

利用日本“Ｙｏｈｋｏｈ”卫星的资料及北京天台２８４０ＭＨｚ的射电观测资料、对１９９２的６月７日的太阳爆发事件进行了分析。结果表明,在这次爆发的脉冲相期间存在着大小两种时间尺度的脉动分量,大尺度的脉动周期约为３０ｓ;小尺度脉动周期为１￣４ｓ,利用硬Ｘ射线成像观测结果,发现大尺度的脉动与硬Ｘ射线源区的一系列变化相对应。中给出了一个环－环相互作用的ＭＨＤ振荡调制物理图像。     

太阳10cm波爆发与共生的硬X射线耀斑中精细结构的分析

利用日本“Ｙｏｈｋｏｈ”卫星的资料及北京天文台２８４０ＭＨｚ的射电观测资料,对１９９２年６月７日的太阳爆发事件进行了分析,结果表明,在这次爆发的脉冲相期间存在着大小两种时间尺度的脉动分量,大尺度的脉动周期约为３０ｓ,小尺度脉动周期为１－４ｓ。利用硬Ｘ射线成像观测结果,发现大尺度的脉动与硬Ｘ射线源区的一系列变化相对应。文中给出了一个环－环相互作用的ＭＨＤ振荡调制物理图像。     

耀斑加速电子能谱的不变点及其意义

在厚靶非热韧致辐射模型下,考察产生耀斑硬Ｘ 射线暴的非热电子幂律能谱随时间的变化。结果发现,对有些耀斑,不同时刻的非热电子能谱总是具有一个粗略的共同交点。该交点可能反映了有些电子加速机制的固有性质———饱和及低端阈能。     

耀斑软X射线流量的统计性质

为了更定量地研究太阳耀斑软X射线辐射的统计性质,发展了一套对于给定峰值流量区间的耀斑的自动识别程序,并用它分析了从1980年到2013年GOES(Geostationary Operational Environmental Satellite)在两个软X射线波段上对太阳耀斑的观测.研究发现耀斑软X射线流量在峰值附近变化的统计特征和耀斑流量峰值的绝对大小无关:平均而言耀斑流量的上升时间约是下降时间的一半,而且高能量通道的上升和下降时间比相应的低能量通道时间要短,但是这些时间还是会随着耀斑流量变化幅度的增加而增加.     

2002年7月23日X射线耀斑的RHESSI和TRACE观测物理图像

通过对比分析TRACE195A和RHESSI的X射线及Ha的图像，发现2002年7月23日的X4.8级耀斑的主体是一个典型的双带耀斑，它的Ha及TRACE195A的图像都显现出明显的双带耀斑特征，TRACE195A的像还呈现一个环拱结构，其环拱的足点与TRACE的亮带并不重合，但TRACE的亮带与X射线像的位置对应很好．在耀斑极大时刻附近，大于38keV的X射线像呈现一个低的环跨在TRACE的双带上，X射线环的顶点及两足点尤其明显，在这个低的环上方，还存在一个在低能量段明显的X射线日冕源，对该耀斑的空间结构及演化特征作了描述，还简单地讨论了一个可能的理论解释．     

第22太阳周活动区M级以上X射线耀斑指数的设计

本文对第２２太阳周中发生过Ｍ级以上的Ｘ射线耀斑对应的３９５个活动区资料进行了耀斑指数的统计，得到的结果：１．２２太阳周Ｍ级以上Ｘ射线耀斑级别综合指数表，２．２２太阳周Ｍ级以上Ｘ射线耀斑总指数表，３．第２２太阳周Ｍ级以上Ｘ射线耀斑总指数随时间的变化曲线，４．第２２周Ｍ级以上Ｘ射耀斑总指数直方图，该图表明第２２太阳周活动的极大年分别是１９８９和１９９１年，为第２３周太阳活动预报提供了可用参数。     

MULTISPECTRAL OBSERVATIONS OF AN ERUPTIVE FLARE

We analyze the pre-flare and impulsive phase of an eruptive (two-ribbon) flare at several wavelengths. The total energy (mechanical plus radiative) released by the flare is 8 x 10³⁰ erg, about a factor 6 higher than the free magnetic energy (1.3 10³⁰ erg) estimated from the non-potentiality of the magnetic field configuration in the flare area. During the impulsive phase, we find a very good time coincidence between the hard X-ray light curve and the light curves for 2 small areas ( 4 in size) in the red wing of the H line and in the He-D₃ line center. This temporal coincidence is compatible with the interpretation that hard X-ray emission is produced by bremsstrahlung of accelerated electron beams striking these dense areas. For the other regions of the H ribbons we find more gradual light curves, suggesting a different energy transport mechanism such as conduction.     

地球自转变化非潮汐项的冰期后地壳反弹解释

本文采用地球上四个最大的冰帽参数，计算了冰帽的融化对地球转动惯量的影响．根据冰期后地壳反弹理论，由现代天体测量空间技术观测资料分析得到的地球自转变化非潮汐项，估计给出了基于１０６６Ｂ地球模型的下地幔粘性系数为１．３５×１０（２２）≥Ｖ（ＬＭ）≤１．９１×１０（２２）Ｐａｓ．结果表明，用冰期后的地壳反弹理论和上述的地球下地幔粘性系数基本可以解释现代空间技术观测得到的地球自转变化中的非潮汐项．     

导致太阳耀斑爆发的暗条扭绞

本文主要根据Ｈａ线心和不同偏带的观测资料，结合紫外ＣＩＶ１５４８谱线的测量结果，分析研究了１９８０年６月２５日ＡＲ２５２２活动区中一段暗条在耀斑爆发前１５分钟所经历的三次逐渐增强的间歇式扭绞，最终导致暗条破裂和耀斑爆发的物理过程，并且用无力场磁绳近似模拟时间条的扭绞运动，估算了暗条扭绞引直怕无力因子ａ的变化，轴向电流增大和守能，讨论了暗条的稳定性，试图对暗条的瓦解和耀斑爆发予以理论解释。     

1989年8月17日耀斑后环系速度场分析

本文给出了１９８９ 年８ 月１７ 日耀斑后环的观测视向速度场,在环内物质在太阳重力、磁场梯度和大气压力梯度联合作用下沿环腿螺旋上升和环内物质密度由环腿向环顶和环足线性递增的假设下,理论上计算了该环系的视向速度场,理论计算和观测结果基本相符,似乎为耀斑物质由色球蒸发作上升运动的观点提供了间接的例证     

ISOLATING THE FOOTPOINT CHARACTERISTICS OF A SOLAR FLARE LOOP

We analyse the physical characteristics of a C5.7 class flare which was observed on 27 September, 1993 using data from the soft X-ray telescope (SXT), the Bragg crystal spectrometer (BCS), and the hard X-ray telescope (HXT) on Yohkoh. The flare takes the form of a simple loop which is much brighter at one of its footpoints than anywhere else for a period of 2 min. During this time there is an increase in the soft X-ray fluxes, and a corresponding peak in hard X-rays. The parameters derived from the hard X-ray and soft X-ray spectra and images are assumed to be from the footpoint. This flare showed two peaks in the non-thermal velocity, the first one simultaneous with the footpoint brightening. The non-thermal velocity corresponding to these first few minutes is unusually large – by a factor of 80%, 68%, and 26% relative to the second peak in the Fexxv, Caxix, and Sxv channels respectively.     

耀斑活动区的向量磁场

本文综述了耀斑活动区向量磁场的基本特征,并对第２３ 太阳活动周的有关研究选题提出了具体的建议。     

CHANGES IN SUNSPOT AND FLOCCULAR SOURCES OF RADIO EMISSION PRECEDING AN IMPORTANCE 2N FLARE ON 23 AUGUST 1988

Based on observations from the Siberian solar radio telescope, and invoking data from other observatories, we investigate preflare changes in the sunspot and floccular sources of radio emission and the development of an importance 2N flare in the chromosphere and corona in the active region on August 23, 1988.It has been ascertained that preflare changes became observable six hours prior to the flare onset and manifested themselves in intense flux fluctuations above the sunspot and in an enhancement of the source emission flux above the flocculus.It is shown that the flare onset is associated with a newly emerged magnetic flux in the form of a pore near the filament and with the appearance of radio sources above the filament. The flare was accompanied by type III radio bursts and a noise storm at meter wavelengths. Coronal mass ejection parameters are estimated from type III burst observations.     

MICROWAVE EMISSION FROM CORONAL HEIGHTS: STUDY OF A NON-THERMAL RADIO FLARE

Two small radio flares following the great gamma-ray burst on 11 June 1991 are studied. We analyse the different association of emission features at microwaves, decimeter waves, and soft and hard X-rays for the events. The first flare has well-defined emission features in microwaves and soft and hard X-rays, and a faint decimetric signature well after the hard X-ray burst. It is not certain if the decimetric event is connected to the burst features. The second event is characterized by an almost simultaneous appearance of hard X-ray burst maxima and decimetric narrowband drift bursts, but soft X-ray emission is missing from the event. With the exception of the possibility that the soft X-ray emission is absorbed along the way, the following models can explain the reported differences in the second event: (1) Microwave emission in the second event is produced by 150 keV electrons spiraling in the magnetic field relatively low in the corona, while the hard X-ray emission is produced at the beginning of the burst near the loop top as thick-target emission. If the bulk of electrons entered the loop, the low-energy electrons would not be effectively mirrored and would eventually hit the footpoints and cause soft X-ray emission by evaporation, which was not observed. The collisions at the loop top would not produce observable plasma heating. The observed decimetric type III bursts could be created by plasma oscillations caused by electron beams traveling along the magnetic field lines at low coronal heights. (2) Microwave emission is caused by electrons with MeV energies trapped in the large magnetic loops, and the electrons are effectively mirrored from the loop footpoints. The hard X-ray emission can come both from the loop top and the loop footpoints as the accelerated lower energy electrons are not mirrored. The low-energy electrons are not, however, sufficient to create observable soft X-ray emission. The type III emission in this case could be formed either at low coronal heights or in local thick regions in the large loops, high in the corona.     

太阳白光耀斑的射电辐射特征:运动Ⅳ型爆发和与耀斑后环共生的短周期脉动现象

通过１９９１ 年６ 月６ 日一个复杂的太阳活动事件（ 包括宽带射电运动Ⅳ型爆发、脉冲相伴生的白光耀斑、耀斑后环及其伴生的射电多重短周期（ 约１ － ４ 秒） 脉动现象等） 的分析,探讨了白光耀斑产生的射电辐射特征,根据太阳白光耀斑和射电运动Ⅳ型爆发产生的物理过程,着重讨论了射电运动Ⅳ型爆发、耀斑后环和短周期脉动现象,并认为它们可能是白光耀斑的对应物     

1974年10月11日白光耀斑的光谱分析

１９７４年１０月１１日耀斑的光谱分析表明，连续发射和微波爆发几乎同时达到极大。在连续辐射极大时刻出现了高项巴耳末发射线和微弱的巴耳末跳跃，所有这些说明这个耀斑是Ｉ型白光耀斑。我们发现，在这个耀斑连续发射的极大时刻，ＣａＩＩＫ线的Ｋ１处强度大大增强，约达到连续辐射强度的一半，对应的辐射温度达到５７１６Ｋ。这个反常增强的持续时间小于４分钟。现有的半经验模型似不能给出这样的结果。色球压缩区也不能给出解释