A hard X-ray sigmoidal structure during the initial phase of the 2003 october 29x10 flare

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 太阳活动的多波段观测研究团组

	A hard X-ray sigmoidal structure during the initial phase of the 2003 october 29x10 flare
	Ji, Haisheng1,2 ; Wang, Haimin 2; Liu, Chang 2; Dennis, Brian R.3
刊名	ASTROPHYSICAL JOURNAL
	2008-06-10
卷号	680 期号:1 页码:734-739
关键词	sun : flares sun : magnetic fields sun : X-rays, gamma rays
ISSN号	0004-637X
英文摘要	We find a hard X-ray (HXR) sigmoidal ( S-shaped) structure observed by RHESSI between 6 and 150 keV during the initial phase of the X10 flare of 2003 October 29. Its counterparts are seen with the Solar X-Ray Imager and TRACE. The flare evolves from a sigmoid to an arcade phase as observed in TRACE 195 8 images. According to the spatial structure of HXR emission, the flare process can be divided into two different phases. During the first phase, HXR emission in different energy ranges shares a similar sigmoidal evolving structure. The structure appears to contract initially as shown by the time profile of the separation between the two footpoints ( FPs) at the ends of the HXR sigmoid. During the second phase, HXR emission in the lower energy range (less than or similar to 30 keV) evolves into two sources located along the neutral line. Meanwhile, the FPs in the higher energies (greater than or similar to 30 keV) move apart as usual. During the whole flaring process, the value of the flare shear, defined as the angle between the line connecting two FPs and the line perpendicular to the neutral line, decreases steadily. We conclude that the flare was triggered by magnetic reconnection near the center of the sigmoid. The converging and unshearing motion during the sigmoid period is explained by continuing magnetic reconnection driven by the erupting sigmoidal flux rope. The reconnection progresses from highly sheared magnetic field lines to less sheared field lines surrounding the flux rope.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	CORONAL MASS EJECTIONS ; SOLAR-FLARES ; MAGNETIC RECONNECTION ; X10 FLARE ; CURRENT SHEET ; FLUX ROPES ; RHESSI ; RELAXATION ; SHRINKAGE ; ERUPTIONS
收录类别	SCI
语种	英语
WOS记录号	WOS:000256500800061
公开日期	2011-12-30
内容类型	期刊论文
源URL	[http://159.226.72.40/handle/332002/2025]
专题	紫金山天文台_太阳活动的多波段观测研究团组
作者单位	1.Purple Mt Observ, Nanjing 210008, Peoples R China 2.New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA 3.NASA, Goddard Space Flight Ctr, Solar Phys Lab, Heliophys Sci Div, Greenbelt, MD 20771 USA
推荐引用方式 GB/T 7714	Ji, Haisheng,Wang, Haimin,Liu, Chang,et al. A hard X-ray sigmoidal structure during the initial phase of the 2003 october 29x10 flare[J]. ASTROPHYSICAL JOURNAL,2008,680(1):734-739.
APA	Ji, Haisheng,Wang, Haimin,Liu, Chang,&Dennis, Brian R..(2008).A hard X-ray sigmoidal structure during the initial phase of the 2003 october 29x10 flare.ASTROPHYSICAL JOURNAL,680(1),734-739.
MLA	Ji, Haisheng,et al."A hard X-ray sigmoidal structure during the initial phase of the 2003 october 29x10 flare".ASTROPHYSICAL JOURNAL 680.1(2008):734-739.