内日冕的绿线强度分布研究

Study of the Intensity Distribution of the Green Line in the Inner Corona

日冕是太阳大气活动的关键区域,是日地空间天气的源头.受观测限制,对日冕低层大气等离子体结构和磁场状态的研究非常欠缺,国际上对于可见光波段日冕低层大气的亮度分层研究很少.利用丽江日冕仪YOGIS(Yunnan Green-line Imaging System)的日冕绿线(Fe_(ⅩⅣ)5303Å)观测资料,对内日冕区域(1.03R⊙-1.25R⊙,R⊙表示太阳半径)亮结构及其中冕环进行了有效的强度衰减分析.对亮结构的强度在太阳径向高度上进行了指数衰减拟合,比较这些拟合结果发现所得到的静态内冕环的衰减指数在一固定值附近.然后将比较明显的冕环提取出来,通过对不同高度的绿线强度进行指数拟合,得出的衰减指数与亮结构中也比较相近,这对进一步研究日冕中的各项物理参数演化提供了参考.

The corona is a key region of solar atmospheric activity,and the source of solar-terrestrial space weather.Limited by observation,research on the plasma structure and magnetic field state of the lower coronal atmosphere is still very lacking,and there are few international studies on the brightness stratification of the lower coronal atmosphere in the visible light band.In this paper,the coronal green line(Fe_(ⅩⅣ)5303Å)observation data of Lijiang coronagraph YOGIS(Yunnan Green-line Imaging System)is used to analyze the bright structure and mid-coronal loops in the inner coronal region(1.03R⊙-1.25R⊙)effectively.By fitting the exponential decay of the intensity of the bright structures at the radial height of the sun,comparing these fitting results,it is found that the decay index of the static inner coronal loops obtained is around a fixed value.Then,the more obvious coronal loops are extracted,and by performing the same exponential fitting on the intensities of different heights,the obtained decay index is also relatively similar to that of the bright structure,which provides a reference for further study of the evolution of physical parameters in the corona.