Generating artificial light curves: revisited and updated
Generating artificial light curves: revisited and updated
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DOI：
10.1093/mnras/stt764
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发表时间：
2013-08-01
影响因子：
4.8
通讯作者：
Papadakis, I. E.
中科院分区：
文献类型：
--
作者：
Emmanoulopoulos, D.;McHardy, I. M.;Papadakis, I. E.
具有已知统计和可变性特性的人造光变曲线的产生在天体物理学中非常重要。巩固互相关研究期间的置信水平、了解采样不规则性引起的人为因素、为未来天文台建立检测极限只是模拟数据集的一些应用。目前，广泛使用的幅度和相位随机化方法能够产生具有给定基础功率谱密度（PSD）但严格高斯分布的人造光曲线。这一限制是一个重大限制，因为大多数光变曲线，例如活动星系核、X射线双星、伽马射线爆发都表现出与高斯性的强烈偏差，在其光变曲线中表现出“类爆发”事件，产生长尾概率密度函数（PDF）。在本研究中，我们提出了一种简单的方法，能够精确地再现与观测到的光变曲线或理论模型的 PSD 和 PDF 相匹配的光变曲线。 PDF 可以代表观测数据的父分布或实际分布，具体取决于针对给定源进行的研究。最终的人造光曲线包含观察到的光源或理论模型的所有统计和变异特性，即分别相同的 PDF 和 PSD。在可重复研究的框架内，本文中使用的代码和说明性示例均以交互式数学笔记本的形式公开提供。
The production of artificial light curves with known statistical and variability properties is of great importance in astrophysics. Consolidating the confidence levels during cross-correlation studies, understanding the artefacts induced by sampling irregularities, establishing detection limits for future observatories are just some of the applications of simulated data sets. Currently, the widely used methodology of amplitude and phase randomization is able to produce artificial light curves which have a given underlying power spectral density (PSD) but which are strictly Gaussian distributed. This restriction is a significant limitation, since the majority of the light curves, e.g. active galactic nuclei, X-ray binaries, gamma-ray bursts, show strong deviations from Gaussianity exhibiting 'burst-like' events in their light curves yielding long-tailed probability density functions (PDFs). In this study, we propose a simple method which is able to precisely reproduce light curves which match both the PSD and the PDF of either an observed light curve or a theoretical model. The PDF can be representative of either the parent distribution or the actual distribution of the observed data, depending on the study to be conducted for a given source. The final artificial light curves contain all of the statistical and variability properties of the observed source or theoretical model, i.e. the same PDF and PSD, respectively. Within the framework of Reproducible Research, the code and the illustrative example used in this paper are both made publicly available in the form of an interactive mathematica notebook.