论文标题
MOA-2019-BLG-008LB：在行星/棕色矮人边界处对物体的新微透镜检测
MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary
论文作者
论文摘要
我们报告了MOA-2019-BLG-008的观察，分析和解释。通过二进制镜头模型，最好描述光度光曲线中观察到的异常。在此模型中，源未交叉苛刻，也没有观察到有限的源效应。因此，角度爱因斯坦环半径不能单独从光曲线中测量。但是，大约80天的大事件持续时间可以精确测量微透析视差。除了对角半径的约束以及源的明显亮度之外，我们还采用了besancon和Galmod银河模型来估计镜头的物理性质。我们发现两个银河系模型的预测之间有着极好的一致性：该同伴可能是棕色矮人沙漠的居民，大约30 mjup，宿主是主要序列矮人恒星。镜头位于视线到银河凸起的距离，距离为4 kpc的距离较小。我们估计，在大约10年内，镜头和源将通过55个MAS分离，并且可以通过使用地面或空间基观测器的高分辨率成像来确认镜头系统的确切性质。
We report on the observations, analysis and interpretation of the microlensing event MOA-2019- BLG-008. The observed anomaly in the photometric light curve is best described through a binary lens model. In this model, the source did not cross caustics and no finite source effects were observed. Therefore the angular Einstein ring radius cannot be measured from the light curve alone. However, the large event duration, t E about 80 days, allows a precise measurement of the microlensing parallax. In addition to the constraints on the angular radius and the apparent brightness I s of the source, we employ the Besancon and GalMod galactic models to estimate the physical properties of the lens. We find excellent agreement between the predictions of the two Galactic models: the companion is likely a resident of the brown dwarf desert with a mass Mp about 30 MJup and the host is a main sequence dwarf star. The lens lies along the line of sight to the Galactic Bulge, at a distance of less then4 kpc. We estimate that in about 10 years, the lens and source will be separated by 55 mas, and it will be possible to confirm the exact nature of the lensing system by using high-resolution imaging from ground or space-based observatories.
