Spectrophotometric Resolution of Stellar Surfaces with Microlensing
Spectrophotometric Resolution of Stellar Surfaces with Microlensing
复制标题
利用微透镜对恒星表面进行分光光度分辨率
DOI：
10.1086/306867
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Andrew Gould
中科院分区：
文献类型：
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作者：
B. Gaudi;Andrew Gould;Andrew Gould
微透镜是研究恒星大气的有力工具，因为当源穿过形式上无限放大的区域（焦散）时，星星的表面被解析，从而允许人们用光度学和光谱学测量径向强度分布。然而，焦散性穿越事件相对罕见，监测它们需要大量应用望远镜资源。因此，必须量化精确测量强度分布所需的观测参数。我们计算恢复的径向强度分布作为一个函数的unlensed通量，源半径，恢复的强度分布的空间分辨率，和焦散交叉时间的两个主要类型的焦散：点质量和二元透镜的预期误差。我们证明，在这两种情况下，这些参数和所产生的误差之间存在简单的比例关系。我们发现，作为恢复的配置文件的空间分辨率的函数的误差，由径向箱的数量参数化，增加为N，大大快于天真的N½R的期望。最后，我们讨论了二元焦散交叉事件和点透镜事件的相对优势。双星事件更常见，更容易计划，并提供有关恒星大气的更均匀的信息;然而，具有低影响参数的点质量事件的子类可以提供更多的信息，前提是它们可以及时识别以启动观测。
Microlensing is a powerful tool for studying stellar atmospheres, because as the source crosses regions of formally infinite magnification (caustics), the surface of the star is resolved, thereby allowing one to measure the radial intensity profile both photometrically and spectroscopically. However, caustic crossing events are relatively rare and monitoring them requires intensive application of telescope resources. It is therefore essential that the observational parameters needed to accurately measure the intensity profile are quantified. We calculate the expected errors in the recovered radial intensity profile as a function of the unlensed flux, source radius, spatial resolution of the recovered intensity profile, and caustic crossing time for the two principle types of caustics: point-mass and binary lenses. We demonstrate that for both cases there exist simple scaling relations between these parameters and the resultant errors. We find that the error as a function of the spatial resolution of the recovered profile, parameterized by the number of radial bins, increases as N, considerably faster than the naive N½R expectation. Finally, we discuss the relative advantages of binary caustic-crossing events and point-lens events. Binary events are more common, easier to plan for, and provide more homogeneous information about the stellar atmosphere; however, a subclass of point-mass events with low impact parameters can provide dramatically more information provided that they can be recognized in time to initiate observations.
巴黎天体物理研究所（法国）
DOI：
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