Spatial and Spectral Behaviors of Solar Flares Observed in Microwaves

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

	Spatial and Spectral Behaviors of Solar Flares Observed in Microwaves
	Ning, Zongjun1 ; Cao, Wenda 2
刊名	SOLAR PHYSICS
	2009-07-01
卷号	257 期号:2 页码:335-350
关键词	Flares Radio radiation
ISSN号	0038-0938
英文摘要	The spatial and spectral behaviors of two solar flares observed by the Nobeyama Radioheliograph (NoRH) on 24 August 2002 and 22 August 2005 are explored. They were observed with a single loop-top source and double footpoint sources at the beginning, then with looplike structures for the rest of the event. NoRH has high spatial and temporal resolution at the two frequencies of 17 and 34 GHz where a nonthermal radio source is often optically thin. Such capabilities give us an opportunity to study the spatial and spectral behaviors of different microwave sources. The 24 August 2002 flare displayed a soft -aEuro parts per thousand hard -aEuro parts per thousand soft (SHS) spectral pattern in the rising -aEuro parts per thousand peak -aEuro parts per thousand decay phases at 34 GHz, which was also observed for the spectral behavior of both loop-top and footpoint sources. In contrast, the 22 August 2005 flare showed a soft -aEuro parts per thousand hard -aEuro parts per thousand harder (SHH) spectral pattern for its both loop-top and footpoint sources. It is interesting that this event showed a harder spectrum in the early rising phase. We found a positive correlation between the spectral index and microwave flux in both the loop-top source and the footpoint sources in both events. The conclusions drawn from the flux index could apply to the electron index as well, because of their simple linear relationship under the assumption of nonthermal gyrosynchrotron mechanism. Such a property of spatial and spectral behaviors of microwave sources gives an observational constraint on the electron acceleration mechanism and electron propagation.
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]	X-RAY-EMISSION ; LOOP-TOP ; ENERGETIC ELECTRONS ; MAGNETIC RECONNECTION ; FOOTPOINT SOURCES ; FLARING LOOPS ; BURSTS ; EVOLUTION ; RHESSI ; PULSATIONS
收录类别	SCI
语种	英语
WOS记录号	WOS:000267111100009
公开日期	2011-12-08
内容类型	期刊论文
源URL	[http://159.226.72.40/handle/332002/1543]
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 210093, Peoples R China 2.New Jersey Inst Technol, Ctr Solar Terr Res, Newark, NJ 07102 USA
推荐引用方式 GB/T 7714	Ning, Zongjun,Cao, Wenda. Spatial and Spectral Behaviors of Solar Flares Observed in Microwaves[J]. SOLAR PHYSICS,2009,257(2):335-350.
APA	Ning, Zongjun,&Cao, Wenda.(2009).Spatial and Spectral Behaviors of Solar Flares Observed in Microwaves.SOLAR PHYSICS,257(2),335-350.
MLA	Ning, Zongjun,et al."Spatial and Spectral Behaviors of Solar Flares Observed in Microwaves".SOLAR PHYSICS 257.2(2009):335-350.