2002年7月23日X射线耀斑的RHESSI和TRACE观测物理图像

A Scenario of the X4.8 Flare on 23 July 2002 Manifested by RHESSI and TRACE Observations

通过对比分析TRACE195A和RHESSI的X射线及H_α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H_α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。

Through inter-comparison among TRACE, RHESSI, and H_α images of the X4.8 flare on 23 July 2002, we found that it is a typical two ribbon flares. The H_α and TRACE195Aimages are all shown to be in two-ribbon patterns, while the TRACE 195Aimages show also a loop-arch whose footpoints have a little deviation from the TRACE 195Aribbons. The ribbons of TRACE 195Aare in good match to the higher en- ergy hard X-ray images. During the impulsive phase, the hard X-ray images above 38 keV present a low--lying loop connecting the two ribbons of TRACE 195A. Above the low-lying loop, there is a coronal low energy hard X-ray source. The spatial structure and evolutionary patterns as a whole are presented. The possible theoretical explanations are briefly discussed.