FAst STatistics for weak Lensing (FASTLens): fast method for weak lensing statistics and map making
FAst STatistics for weak Lensing (FASTLens): fast method for weak lensing statistics and map making
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弱透镜的快速统计（FASTLens）：弱透镜统计和地图制作的快速方法
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
J. Fadili
中科院分区：
文献类型：
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作者：
S. Pires;J. Starck;A. Amara;R. Teyssier;A. Réfrégier;J. Fadili
随着数据集越来越大，弱透镜测量能够以越来越高的精度测量宇宙学参数。然而，这种准确性的提高也对用于提取现有信息的统计工具提出了更高的要求。到目前为止，大多数透镜分析使用的是宇宙切变场的两点统计。它们可以直接使用两点相关函数进行研究，也可以在傅里叶空间中使用功率谱进行研究。但分析弱透镜数据不可避免地涉及到遮蔽区域，例如从视野中移除明亮的恒星。掩盖恒星是一种常见的做法，但数据中的差距需要妥善处理。在这篇文章中，我们展示了修复技术如何使我们能够仅用NlogN运算来适当地填补这些空白，从而产生一种新的图像，从该图像我们可以直接地计算功率谱和双谱，并且具有非常好的精度。然后，我们提出了一种用极坐标拟合法计算双谱的新方法，该算法的主要优点是避免了傅立叶域中的任何内插。最后，我们提出了一种从剪切观测重建暗物质质量图的新方法，该方法结合了这一新的修复概念。基于3D N-Body模拟的一系列示例说明了结果。
With increasingly large data sets, weak lensing measurements are able to measure cosmological parameters with ever-greater precision. However, this increased accuracy also places greater demands on the statistical tools used to extract the available information. To date, the majority of lensing analyses use the two-point statistics of the cosmic shear field. These can be either studied directly using the two-point correlation function or in Fourier space, using the power spectrum. But analysing weak lensing data inevitably involves the masking out of regions, for example to remove bright stars from the field. Masking out the stars is common practice but the gaps in the data need proper handling. In this paper, we show how an inpainting technique allows us to properly fill in these gaps with only NlogN operations, leading to a new image from which we can compute straightforwardly and with a very good accuracy both the power spectrum and the bispectrum. We then propose a new method to compute the bispectrum with a polar FIT algorithm, which has the main advantage of avoiding any interpolation in the Fourier domain. Finally, we propose a new method for dark matter mass map reconstruction from shear observations, which integrates this new inpainting concept. A range of examples based on 3D N-body simulations illustrates the results.
DOI：
10.1111/j.1365-2966.2008.12902.x
发表时间：
2007-12
影响因子：
4.8
作者：
J. Berg'e;F. Pacaud;Alexandre R'efr'egier;R. Massey;M. Pierre;A. Amara;M. Birkinshaw;S. Paulin-Henriksson;Graham P. Smith;J. P. I. F. Astronomy;Bonn Caltech University of Bristol University of Birmin Victoria-Bonn-Caltech-University-of-Bristol-University-of-121343140
通讯作者：
J. Berg'e;F. Pacaud;Alexandre R'efr'egier;R. Massey;M. Pierre;A. Amara;M. Birkinshaw;S. Paulin-Henriksson;Graham P. Smith;J. P. I. F. Astronomy;Bonn Caltech University of Bristol University of Birmin Victoria-Bonn-Caltech-University-of-Bristol-University-of-121343140