Spectroscopic properties of dynamical chromospheric processes in a confined solar flare

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 太阳高能及相关物理过程研究团组

	Spectroscopic properties of dynamical chromospheric processes in a confined solar flare
	Li, H; You, J; Du, Q
刊名	SOLAR PHYSICS
	2006-05-01
卷号	235 期号:1-2 页码:107-123
关键词	LINE ASYMMETRIES MULTIWAVELENGTH SPECTRA
ISSN号	0038-0938
英文摘要	We present our results of high temporal resolution spectroscopic observation and study in H alpha, Ca II, and He I lines for the 2B/M1.9 confined disk flare on September 9, 2001, combining with GOES soft X-ray (SXR) and Yohkoh hard X-ray (HXR) observations. Apparent redshifted and red-asymmetric profiles were observed in the initial phase. The redshift lasted until the late phase. The derived velocity depends on both the spectral line and the used method. The redshift velocities computed from the line centers of the observed emission profiles (upsilon(0)) are of the order of 10 km s(-1) both inside and outside the streak area. However, the velocities determined from the excess profiles by the bisector method (upsilon) are larger in the streak (18-50 km s(-1)). Both upsilon and the red full widths (RFWs) derived from the excess profiles show temporal variations similar to the HXR light-curve in the streak area. Moreover, the H alpha line wings of nonthermal characteristics, the redshift velocities, and the lifetime of impulsive broadening suggest that the streak is related to nonthermal electron bombardment. Spectral simulations reveal that we cannot reproduce the observed profiles in the three lines simultaneously with a set of parameters, indicating that the flare atmosphere was not homogeneous along the line-of-sight. Most of the observed H alpha profiles showed a 'flat-top' structure, implying the flare plasma was optically thick for this line. The electron temperatures (T-e) deduced from the line-center intensity of the three lines are similar and estimated to be higher than 7200 K. The obvious central reversal of the H alpha profiles due to absorption of materials in the impulsive phase lasted more than 2 min. However, the far blue wings of the Ca II profiles in the impulsive phase showed low-intensity emission, which is suggestive of the existence of large turbulence or macroscopic motion (> 50 km s(-1)), which is inconsistent with the current flare model.
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]	LINE ASYMMETRIES ; MULTIWAVELENGTH ; SPECTRA
收录类别	SCI
语种	英语
WOS记录号	WOS:000237505800007
公开日期	2012-02-07
内容类型	期刊论文
源URL	[http://159.226.72.40/handle/332002/3594]
专题	紫金山天文台_太阳高能及相关物理过程研究团组
作者单位	Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China
推荐引用方式 GB/T 7714	Li, H,You, J,Du, Q. Spectroscopic properties of dynamical chromospheric processes in a confined solar flare[J]. SOLAR PHYSICS,2006,235(1-2):107-123.
APA	Li, H,You, J,&Du, Q.(2006).Spectroscopic properties of dynamical chromospheric processes in a confined solar flare.SOLAR PHYSICS,235(1-2),107-123.
MLA	Li, H,et al."Spectroscopic properties of dynamical chromospheric processes in a confined solar flare".SOLAR PHYSICS 235.1-2(2006):107-123.