Einstein Radii from Binary-Source Lensing Events
Einstein Radii from Binary-Source Lensing Events
复制标题
二元源透镜事件的爱因斯坦半径
DOI：
10.1086/303944
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
A. Gould
中科院分区：
文献类型：
--
作者：
C. Han;A. Gould
我们证明，投影在源平面上的透镜的爱因斯坦环半径和横向速度 r̂E 和 v̂ 可以根据双源事件的光变曲线确定，然后通过光谱确定源恒星的轨道元素。这一测定利用了与通过有限源效应测量爱因斯坦环半径相同的原理。对于源星轨道周期远长于爱因斯坦时标P≫tE的情况，在确定r̂E时存在单一双重简并性。然而，当 P ≲ tE 时，简并性通常可以通过利用双源系统的轨道运动来打破。对于在大麦哲伦星云 (LMC) 方向看到的源 V < 20 的所有透镜事件的约 8%，人们可以明确地确定透镜是否是银河系的，或者它们是否位于 LMC 本身。此外，我们建议将食双星作为引力透镜实验的来源。
We show that the Einstein ring radius and transverse speed of a lens projected on the source plane, r̂E and v̂, can be determined from the light curve of a binary-source event, followed by the spectroscopic determination of the orbital elements of the source stars. The determination makes use of the same principle that allows one to measure the Einstein ring radii from finite-source effects. For the case when the orbital period of the source stars is much longer than the Einstein timescale, P ≫ tE, there exists a single twofold degeneracy in determining r̂E. However, when P ≲ tE the degeneracy can often be broken by making use of the binary-source system's orbital motion. For ~8% of all lensing events with sources V < 20 seen toward the Large Magellanic Cloud (LMC), one can unambiguously determine whether the lenses are Galactic or whether they lie in the LMC itself. In addition, we propose to include eclipsing binaries as sources for gravitational lensing experiments.