标题： 弱引力透镜调查中三点内在对齐自相关性的自校准 显示英文标题

标题： Self-Calibration for 3-point Intrinsic Alignment Auto-Correlations in Weak Lensing Surveys

摘要： 弱引力透镜信号（宇宙剪切）已被证明受到各种类型的星系内禀对齐（IA）相关性的强烈污染，这给精确的弱引力透镜测量带来了障碍。 IA信号的红移依赖性已在两点水平上被用来通过仅测量大红移区间之间的交叉相关性来减少这种污染，这显著降低了星系内禀椭率-内禀椭率（II）相关性。 还提出了一种基于IA相关性红移依赖性的自校准技术，作为从透镜信号中去除两点IA污染的方法。 我们在此探讨IA和透镜三阶谱的红移依赖性，以在三点水平上提出IA自相关性的自校准方法（即GGI、GII和III），这可以在不假设任何特定IA模型的情况下很好地理解。 我们发现，未来的弱引力透镜调查将在$|\Delta z^P|\le 0.2$的范围内测量独特的IA红移依赖性。 使用保守的光度红移精度估计，我们描述了总IA信号的三点自校准技术，这可以通过光度红移区间大小为$\sim 0.01$的透镜分层技术来完成。 我们发现，三点自校准可以在红移分离的适度约束下达到与两点技术相当的精度。 这使得此处提出的三点IA自相关性自校准技术能够显著减少IA污染对弱引力透镜三阶谱的污染。 显示英文摘要

摘要： The weak lensing signal (cosmic shear) has been shown to be strongly contaminated by the various types of galaxy intrinsic alignment (IA) correlations, which poses a barrier to precision weak lensing measurements. The redshift dependence of the IA signal has been used at the 2-point level to reduce this contamination by only measuring cross-correlations between large redshift bins, which significantly reduces the galaxy intrinsic ellipticity - intrinsic ellipticity (II) correlation. A self-calibration technique based on the redshift dependences of the IA correlations has also been proposed as a means to remove the 2-point IA contamination from the lensing signal. We explore here the redshift dependences of the IA and lensing bispectra in order to propose a self-calibration of the IA auto-correlations at the 3-point level (i.e. GGI, GII, and III), which can be well understood without the assumption of any particular IA model. We find that future weak lensing surveys will be able to measure the distinctive IA redshift dependence over ranges of $|\Delta z^P|\le 0.2$. Using conservative estimates of photo-z accuracy, we describe the 3-point self-calibration technique for the total IA signal, which can be accomplished through lensing tomography of photo-z bin size $\sim 0.01$. We find that the 3-point self-calibration can function at the accuracy of the 2-point technique with modest constraints in redshift separation. This allows the 3-point IA auto-correlation self-calibration technique proposed here to significantly reduce the contamination of the IA contamination to the weak lensing bispectrum.