STATISTICAL ANALYSIS OF FLARING LOOPS OBSERVED BY NOBEYAMA RADIOHELIOGRAPH. I. COMPARISON OF LOOPTOP AND FOOTPOINTS

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

	STATISTICAL ANALYSIS OF FLARING LOOPS OBSERVED BY NOBEYAMA RADIOHELIOGRAPH. I. COMPARISON OF LOOPTOP AND FOOTPOINTS
	Huang, Guangli 1; Nakajima, Hiroshi 2
刊名	ASTROPHYSICAL JOURNAL
	2009-05-01
卷号	696 期号:1 页码:136-142
关键词	Sun: flares Sun: magnetic fields Sun: radio radiation
ISSN号	0004-637X
英文摘要	Twenty-four events with looplike structures at 17 and 34 GHz are selected from the flare list of Nobeyama Radioheliograph. We obtained the brightness temperatures at 17 and 34 GHz, the polarization degrees at 17 GHz, and the power-law spectral indices at the radio peak time for one looptop (LT) and two footpoints (FPs) of each event. We also calculated the magnetic field strengths and the column depths of nonthermal electrons in the LT and FPs of each event, using the equations modified from the gyrosynchrotron equations by Dulk. The main statistical results from those data are summarized as follows. (1) The spectral indices, the brightness temperatures at 17 and 34 GHz, the polarization degrees at 17 GHz, the calculated magnetic field strengths, and the calculated column densities of nonthermal electrons are always positively correlated between the LT and the two FPs of the selected events. (2) About one-half of the events have the brightest LT at 17 and 34 GHz. (3) The spectral indices in the two FPs are larger (softer) than those in the corresponding LT in most events. (4) The calculated magnetic field strengths in the two FPs are always larger than those in the corresponding LT. (5) Most of the events have the same positive or negative polarization sense in the LT and the two FPs. (6) The brightness temperatures at 17 and 34 GHz in each of the LT and the two FPs statistically decrease with their spectral indices and the calculated magnetic field strengths, but increase with their calculated column densities of nonthermal electrons. Moreover, we try to discuss the possible causes of the present statistical results.
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]	SOLAR MICROWAVE-BURSTS ; SPATIAL-DISTRIBUTION ; MAGNETIC-FIELD ; RADIO-EMISSION ; FLARES ; POLARIZATION ; MODEL ; TOP ; PROPAGATION ; ELECTRONS
收录类别	SCI
语种	英语
WOS记录号	WOS:000265350100013
公开日期	2011-12-08
内容类型	期刊论文
源URL	[http://159.226.72.40/handle/332002/1545]
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.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China 2.Nobeyama Radio Observ, Minamimaki, Nagano 3841305, Japan
推荐引用方式 GB/T 7714	Huang, Guangli,Nakajima, Hiroshi. STATISTICAL ANALYSIS OF FLARING LOOPS OBSERVED BY NOBEYAMA RADIOHELIOGRAPH. I. COMPARISON OF LOOPTOP AND FOOTPOINTS[J]. ASTROPHYSICAL JOURNAL,2009,696(1):136-142.
APA	Huang, Guangli,&Nakajima, Hiroshi.(2009).STATISTICAL ANALYSIS OF FLARING LOOPS OBSERVED BY NOBEYAMA RADIOHELIOGRAPH. I. COMPARISON OF LOOPTOP AND FOOTPOINTS.ASTROPHYSICAL JOURNAL,696(1),136-142.
MLA	Huang, Guangli,et al."STATISTICAL ANALYSIS OF FLARING LOOPS OBSERVED BY NOBEYAMA RADIOHELIOGRAPH. I. COMPARISON OF LOOPTOP AND FOOTPOINTS".ASTROPHYSICAL JOURNAL 696.1(2009):136-142.