Line profiles of the two-phase medium broad-line region in active galactic nuclei

NTSC-IR

	Line profiles of the two-phase medium broad-line region in active galactic nuclei
	Xue, SJ ; Lin, XB ; Cheng, FZ ; Kwan, J
	1996-08-01
发表期刊	SCIENCE IN CHINA SERIES A-MATHEMATICS PHYSICS ASTRONOMY
ISSN	1006-9283
卷号	39 期号:8 页码:883-896
摘要	In the framework of BLR in AGNs, i.e. large number of small, cold and dense emission-line clouds immerging in an intercloud hot medium a delicate radiation model for a typical emission cloud is established, in which the backside photoionization of the cloud against the central continuum source by the scattered diffuse continuum in the hot medium is considered. Under the assumption of the radial kinematics of the BLR clouds, the line profiles for the two important UV emission-lines, Ly alpha and CIV lambda 1549 are computed; and based on these calculations, various physical factors that affect the properties of the emission-line profiles are discussed. It is concluded that: (i) when the BLR clouds is inflow, there exists a confining hot medium with density around 2x10(5) cm(-3). In this case, theoretical line profiles agree well with the observational; (ii) both symmetric Ly alpha and nearly symmetric CIV line profiles show blue velocity shifts, the quantities of which are sensitive to the cutoff of the outer radius of the BLR. It is suggested that this cutoff effect is physical background to explain the observations that high ionization lines in the spectra of AGNs have some systematic blue shifts relative to those low ionization lines which usually characterize their source system velocities.
关键词	active galactic nuclei (AGNs) broad line region (BLR) emission line profiles
关键词[WOS]	EMISSION ; QUASARS ; NGC-5548 ; STEPS ; SIZE
语种	英语
WOS研究方向	Mathematics
WOS类目	Mathematics, Applied ; Mathematics
WOS记录号	WOS:A1996WA87100010
出版者	SCIENCE CHINA PRESS
引用统计
文献类型	期刊论文
条目标识符	http://210.72.145.45/handle/361003/11507
专题	中国科学院国家授时中心
通讯作者	Xue, SJ
作者单位	1.UNIV MASSACHUSETTS,DEPT PHYS & ASTROPHYS,AMHERST,MA 01003 2.CHINESE ACAD SCI,SHAANXI ASTRON OBSERV,LINTONG 710600,PEOPLES R CHINA
推荐引用方式 GB/T 7714	Xue, SJ,Lin, XB,Cheng, FZ,et al. Line profiles of the two-phase medium broad-line region in active galactic nuclei[J]. SCIENCE IN CHINA SERIES A-MATHEMATICS PHYSICS ASTRONOMY,1996,39(8):883-896.
APA	Xue, SJ,Lin, XB,Cheng, FZ,&Kwan, J.(1996).Line profiles of the two-phase medium broad-line region in active galactic nuclei.SCIENCE IN CHINA SERIES A-MATHEMATICS PHYSICS ASTRONOMY,39(8),883-896.
MLA	Xue, SJ,et al."Line profiles of the two-phase medium broad-line region in active galactic nuclei".SCIENCE IN CHINA SERIES A-MATHEMATICS PHYSICS ASTRONOMY 39.8(1996):883-896.