REPEATABILITY AND ACCURACY OF EXOPLANET ECLIPSE DEPTHS MEASURED WITH POST-CRYOGENIC SPITZER
REPEATABILITY AND ACCURACY OF EXOPLANET ECLIPSE DEPTHS MEASURED WITH POST-CRYOGENIC SPITZER
复制标题
使用后低温斯皮策测量的系外行星食深度的重复性和准确性
DOI：
10.3847/0004-6256/152/2/44
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
L. Storrie
中科院分区：
文献类型：
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作者：
J. Ingalls;J. Krick;Sean Carey;J. Stauffer;P. Lowrance;C. Grillmair;D. Buzasi;D. Deming;Hannah Diamond;T. Evans;G. Morello;K. Stevenson;I. Wong;P. Capak;W. Glaccum;S. Laine;J. Surace;L. Storrie
我们研究的可重复性，可靠性和精度的差分系外行星日食深度测量使用斯皮策太空望远镜上的红阵列相机（IRAC）在后低温使命。我们重新分析了一个现有的4.5 μm数据集，包括10个观测的XO-3b系统在二次日食期间，使用七种不同的技术来消除相关噪声。我们发现，平均而言，对于一个给定的技术，日食深度估计是可重复的，从一个时代到另一个时代，在百万分之156（ppm）。大多数技术得出的日食深度变化不超过光子噪声极限的3倍。所有的方法，但一个准确地评估自己的错误：对于这些方法，个人的测量不确定性是可比的，在10个历元样本的日食深度的分散。为了评估技术的准确性以及澄清仪器和其他测量误差来源之间的差异，我们还分析了10次访问XO-3b的模拟数据集，其中日食深度是已知的。我们发现，三种方法（布利斯映射，像素级解相关和独立分量分析）获得的结果是在三倍的光子限制的真实日食深度。当在10个历元集合上平均时，7种技术中有5种在真实值的60 ppm范围内。斯皮策系外行星数据，如果按照目前的最佳实践获得，并使用本文所述的方法减少，可以测量可重复和准确的单次日食深度，接近光子限制的结果。
We examine the repeatability, reliability, and accuracy of differential exoplanet eclipse depth measurements made using the InfraRed Array Camera (IRAC) on the Spitzer Space Telescope during the post-cryogenic mission. We have re-analyzed an existing 4.5 μm data set, consisting of 10 observations of the XO-3b system during secondary eclipse, using seven different techniques for removing correlated noise. We find that, on average, for a given technique, the eclipse depth estimate is repeatable from epoch to epoch to within 156 parts per million (ppm). Most techniques derive eclipse depths that do not vary by more than a factor 3 of the photon noise limit. All methods but one accurately assess their own errors: for these methods, the individual measurement uncertainties are comparable to the scatter in eclipse depths over the 10 epoch sample. To assess the accuracy of the techniques as well as to clarify the difference between instrumental and other sources of measurement error, we have also analyzed a simulated data set of 10 visits to XO-3b, for which the eclipse depth is known. We find that three of the methods (BLISS mapping, Pixel Level Decorrelation, and Independent Component Analysis) obtain results that are within three times the photon limit of the true eclipse depth. When averaged over the 10 epoch ensemble, 5 out of 7 techniques come within 60 ppm of the true value. Spitzer exoplanet data, if obtained following current best practices and reduced using methods such as those described here, can measure repeatable and accurate single eclipse depths, with close to photon-limited results.