ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS

	ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS
	Chu, Zhe 1,2; Lin, W. P.1,2,3; Yang, Xiaofeng 4
刊名	ASTROPHYSICAL JOURNAL LETTERS
	2013-06-20
卷号	770 期号:2 页码:1
关键词	gravitational lensing: strong methods: analytical
英文摘要	Using an analytical method, we study the singular isothermal quadrupole (SIQ) lens system, which is the simplest lens model that can produce four images. In this case, the radial mass distribution is in accord with the profile of the singular isothermal sphere lens, and the tangential distribution is given by adding a quadrupole on the monopole component. The basic properties of the SIQ lens have been studied in this Letter, including the deflection potential, deflection angle, magnification, critical curve, caustic, pseudo-caustic, and transition locus. Analytical solutions of the image positions and magnifications for the source on axes are derived. We find that naked cusps will appear when the relative intensity k of quadrupole to monopole is larger than 0.6. According to the magnification invariant theory of the SIQ lens, the sum of the signed magnifications of the four images should be equal to unity, as found by Dalal. However, if a source lies in the naked cusp, the summed magnification of the left three images is smaller than the invariant 1. With this simple lens system, we study the situations where a point source infinitely approaches a cusp or a fold. The sum of the magnifications of the cusp image triplet is usually not equal to 0, and it is usually positive for major cusps while negative for minor cusps. Similarly, the sum of magnifications of the fold image pair is usually not equal to 0 either. Nevertheless, the cusp and fold relations are still equal to 0 in that the sum values are divided by infinite absolute magnifications by definition.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	GRAVITATIONAL LENS ; MAGNIFICATION RELATIONS ; SUBSTRUCTURE ; GALAXIES ; SYSTEMS
收录类别	SCI
语种	英语
WOS记录号	WOS:000320709900018
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/18017]
专题	上海天文台_星系宇宙学重点实验室
作者单位	1.Chinese Acad Sci, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, Shanghai 200030, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Shanghai Jiao Tong Univ, Ctr Astron & Astrophys, Shanghai 200240, Peoples R China 4.Nanjing Univ, Sch Astron & Space Sci, Nanjing 210093, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Chu, Zhe,Lin, W. P.,Yang, Xiaofeng. ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS[J]. ASTROPHYSICAL JOURNAL LETTERS,2013,770(2):1.
APA	Chu, Zhe,Lin, W. P.,&Yang, Xiaofeng.(2013).ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS.ASTROPHYSICAL JOURNAL LETTERS,770(2),1.
MLA	Chu, Zhe,et al."ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS".ASTROPHYSICAL JOURNAL LETTERS 770.2(2013):1.