Hexadecapole Approximation in Planetary Microlensing
Hexadecapole Approximation in Planetary Microlensing
复制标题
行星微透镜中的十六极近似
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
A. Gould
中科院分区：
文献类型：
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作者：
A. Gould
微透镜行星探测的频率，特别是在难以建模的高放大率事件中，正在增加。它们的分析可能需要数万个处理器小时或更多，主要是因为测量的高密度和高精度，其建模需要耗时的有限源计算。我表明，这些测量的大部分，那些位于至少一个源直径从焦散或从尖点的延伸，可以使用一个非常简单的十六极近似，这是一个到几个数量级的速度比成熟的有限源计算建模。此外，通过将实际上需要有限源计算的区域限制在几个孤立的“焦散特征”，十六极近似将首次允许强大的“放大图”方法应用于行星轨道运动重要的事件。
The frequency of microlensing planet detections, particularly in difficult-to-model high-magnification events, is increasing. Their analysis can require tens of thousands of processor hours or more, primarily because of the high density and high precision of measurements whose modeling requires time-consuming finite-source calculations. I show that a large fraction of these measurements, those that lie at least one source diameter from a caustic or the extension from a cusp, can be modeled using a very simple hexadecapole approximation, which is one to several orders of magnitude faster than full-fledged finite-source calculations. Moreover, by restricting the regions that actually require finite-source calculations to a few isolated “caustic features,” the hexadecapole approximation will, for the first time, permit the powerful “magnification map” approach to be applied to events for which the planet’s orbital motion is important.