OGLE-2018-BLG-0022: First Prediction of an Astrometric Microlensing Signal from a Photometric Microlensing Event
OGLE-2018-BLG-0022: First Prediction of an Astrometric Microlensing Signal from a Photometric Microlensing Event
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DOI：
10.3847/1538-4357/ab1539
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
C. Han;I. Bond;A. Udalski;A. Gould;V. Bozza;Y. Hirao;A. Cassan;M. Albrow;S. Chung;K. Hwang-K
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文献类型：
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作者：
C. Han;I. Bond;A. Udalski;A. Gould;V. Bozza;Y. Hirao;A. Cassan;M. Albrow;S. Chung;K. Hwang-K
在这项工作中，我们给出了对银河系凸起场探测到的双星微透镜事件OGLE-2018-BLG-0022的分析。来自地面观测的高质量测光数据的密集和连续覆盖，以及对这一长时间尺度事件的空间斯皮策观测，使我们能够唯一地确定单个透镜组件的质量M1=0.40±0.05M⊙和M2=0.13±0.01M⊙。因为透镜-光源的相对视差和矢量透镜-光源的相对自身运动是明确确定的，所以我们同样可以毫不含糊地预测放大图像的光质心(由Gaia卫星观测)与光源的真实位置之间的天体测量偏移。当个别时代的盖亚天体测量数据发布时，这一预测可以得到验证。
In this work, we present the analysis of the binary microlensing event OGLE-2018-BLG-0022 that is detected toward the Galactic bulge field. The dense and continuous coverage with the high-quality photometry data from ground-based observations combined with the space-based Spitzer observations of this long timescale event enables us to uniquely determine the masses M1 = 0.40 ± 0.05 M⊙ and M2 = 0.13 ± 0.01 M⊙ of the individual lens components. Because the lens-source relative parallax and the vector lens-source relative proper motion are unambiguously determined, we can likewise unambiguously predict the astrometric offset between the light centroid of the magnified images (as observed by the Gaia satellite) and the true position of the source. This prediction can be tested when the individual-epoch Gaia astrometric measurements are released.