A NEW TYPE OF AMBIGUITY IN THE PLANET AND BINARY INTERPRETATIONS OF CENTRAL PERTURBATIONS OF HIGH-MAGNIFICATION GRAVITATIONAL MICROLENSING EVENTS

	A NEW TYPE OF AMBIGUITY IN THE PLANET AND BINARY INTERPRETATIONS OF CENTRAL PERTURBATIONS OF HIGH-MAGNIFICATION GRAVITATIONAL MICROLENSING EVENTS
	Choi, JY; Shin, IG; Han, C; Udalski, A; Sumi, T; Gould, A; Bozza, V; Dominik, M; Fouque, P; Horne, K
刊名	ASTROPHYSICAL JOURNAL
	2012-09-01
卷号	756 期号:1
关键词	Galaxy: bulge gravitational lensing: micro
ISSN号	0004-637X
通讯作者	Choi, JY (reprint author), Chungbuk Natl Univ, Inst Astrophys, Dept Phys, Cheongju 371763, South Korea.
产权排序	第二十九完成单位
英文摘要	High-magnification microlensing events provide an important channel to detect planets. Perturbations near the peak of a high-magnification event can be produced either by a planet or a binary companion. It is known that central perturbations induced by both types of companions can be generally distinguished due to the essentially different magnification pattern around caustics. In this paper, we present a case of central perturbations for which it is difficult to distinguish the planetary and binary interpretations. The peak of a lensing light curve affected by this perturbation appears to be blunt and flat. For a planetary case, this perturbation occurs when the source trajectory passes the negative perturbation region behind the back end of an arrowhead-shaped central caustic. For a binary case, a similar perturbation occurs for a source trajectory passing through the negative perturbation region between two cusps of an astroid-shaped caustic. We demonstrate the degeneracy for two high-magnification events of OGLE-2011-BLG-0526 and OGLE-2011-BLG-0950/MOA-2011-BLG-336. For OGLE-2011-BLG-0526, the chi(2) difference between the planetary and binary model is similar to 3, implying that the degeneracy is very severe. For OGLE-2011-BLG-0950/MOA-2011-BLG-336, the stellar binary model is formally excluded with Delta chi(2) similar to 105 and the planetary model is preferred. However, it is difficult to claim a planet discovery because systematic residuals of data from the planetary model are larger than the difference between the planetary and binary models. Considering that two events observed during a single season suffer from such a degeneracy, it is expected that central perturbations experiencing this type of degeneracy is common.
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]	DIFFERENCE IMAGE-ANALYSIS ; JOVIAN-MASS PLANET ; GALACTIC BULGE ; OPTICAL DEPTH ; EXTRASOLAR PLANETS ; LENS IMAGES ; CAUSTICS ; DISCOVERY ; CHANNEL ; SYSTEMS
收录类别	SCI
原文出处	http://iopscience.iop.org/article/10.1088/0004-637X/756/1/48/meta
语种	英语
WOS记录号	WOS:000309044300048
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5216]
专题	云南天文台_恒星物理研究组
推荐引用方式 GB/T 7714	Choi, JY,Shin, IG,Han, C,et al. A NEW TYPE OF AMBIGUITY IN THE PLANET AND BINARY INTERPRETATIONS OF CENTRAL PERTURBATIONS OF HIGH-MAGNIFICATION GRAVITATIONAL MICROLENSING EVENTS[J]. ASTROPHYSICAL JOURNAL,2012,756(1).
APA	Choi, JY.,Shin, IG.,Han, C.,Udalski, A.,Sumi, T.,...&Zub, M.(2012).A NEW TYPE OF AMBIGUITY IN THE PLANET AND BINARY INTERPRETATIONS OF CENTRAL PERTURBATIONS OF HIGH-MAGNIFICATION GRAVITATIONAL MICROLENSING EVENTS.ASTROPHYSICAL JOURNAL,756(1).
MLA	Choi, JY,et al."A NEW TYPE OF AMBIGUITY IN THE PLANET AND BINARY INTERPRETATIONS OF CENTRAL PERTURBATIONS OF HIGH-MAGNIFICATION GRAVITATIONAL MICROLENSING EVENTS".ASTROPHYSICAL JOURNAL 756.1(2012).