论文标题
弱透镜图中的最佳空隙发现器
Optimal void finders in weak lensing maps
论文作者
论文摘要
宇宙空隙是包含大量宇宙学信息的大型结构的关键组成部分。通常,从基础星系分布中鉴定出空隙,这是总物质场的有偏见的示踪剂。先前的作品表明,在弱透镜图中鉴定出的2D空隙 - 弱透镜空隙 - 更好地对应于视线沿线的真实不足区域。在这项工作中,我们研究弱透镜空隙的性质如何通过适应几个流行的空隙发现器来取决于空隙发现器的选择。我们介绍并讨论直接在收敛图中识别空隙与弱透镜峰分布之间的差异。已经特别努力测试这些结果如何受到星系形状噪声的影响,这是弱透镜观测中噪声的主要来源。通过研究每个void Finder的切向剪切轮廓的信噪比(SNR),我们发现直接在收敛图中鉴定出的空隙具有最高的SNR,但也是受星系噪声影响最大的空隙。槽最少受噪声影响,但也具有最低的SNR。识别弱透镜峰分布中空隙的隧道算法表示,在找到大型切向切割剪切SNR和减轻星系噪声的效果之间,这是一个良好的妥协。
Cosmic voids are a key component of the large-scale structure that contain a plethora of cosmological information. Typically, voids are identified from the underlying galaxy distribution, which is a biased tracer of the total matter field. Previous works have shown that 2D voids identified in weak lensing maps -- weak lensing voids -- correspond better to true underdense regions along the line of sight. In this work, we study how the properties of weak lensing voids depend on the choice of void finder, by adapting several popular void finders. We present and discuss the differences between identifying voids directly in the convergence maps, and in the distribution of weak lensing peaks. Particular effort has been made to test how these results are affected by galaxy shape noise, which is a dominant source of noise in weak lensing observations. By studying the signal-to-noise ratios (SNR) for the tangential shear profile of each void finder, we find that voids identified directly in the convergence maps have the highest SNR but are also the ones most affected by galaxy shape noise. Troughs are least affected by noise, but also have the lowest SNR. The tunnel algorithm, which identifies voids in the distribution of weak lensing peaks, represents a good compromise between finding a large tangential shear SNR and mitigating the effect of galaxy shape noise.