Astrometric properties of gravitational binary-microlens events and their applications

被引：25

作者：

Han, C ^{[1
]}

Chu, M

Chang, K

机构：

[1] Chungbuk Natl Univ, Dept Astron & Space Sci, Chongju 361763, South Korea

[2] Yonsei Univ, Dept Astron, Seoul 120749, South Korea

[3] Chungbuk Natl Univ, Dept Phys, Chongju 360764, South Korea

来源：

ASTROPHYSICAL JOURNAL | 1999年 / 526卷 / 01期

关键词：

astrometry; binaries : general; gravitational lensing;

D O I：

10.1086/307996

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

In this paper, we study the astrometric properties of gravitational microlensing events caused by binary lenses. By investigating the centroid shifts for various types of binary-lens events, we find that the deviations of the centroid shift trajectories from the elliptical ones of single-lens events are characterized by distortions, twistings, and big jumps. We study the conditions of binary-lens system configurations and source star trajectories for individual types of deviations. We find dramatic differences in the astrometric centroid shifts for binary-lens microlensing events that would be degenerate had their parameters been determined photometrically. Therefore, when additional astrometric observations of a binary-lens event are available, one can resolve the ambiguity of the binary-lens fit and uniquely determine the binary-lens parameters.

引用

页码：405 / 410

页数：6

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