论文标题
黑暗能源调查3年结果：弱透镜源星系的红移校准
Dark Energy Survey Year 3 Results: Redshift Calibration of the Weak Lensing Source Galaxies
论文作者
论文摘要
确定通过宽场光度实验（例如暗能量调查）观察到的星系的红移分布是用重力透镜映射物质密度场的重要组成部分。在这项工作中，我们描述了用于分配黑暗能源调查的单个弱透镜源星系的方法，第3年弱透镜源目录到四个断层扫描箱，并估算这些箱中的红移分布。作为这些方法在数据中的首次应用，我们验证了提出的假设适用于DES Y3弱透镜源星系，并对系统不确定性进行了全面处理。我们的方法包括结合来自三个独立可能性函数的信息：自组织地图$ p（z）$（SOMPZ），这是一种从星系光度法约束红移的方法；聚类红移（WZ），对星系密度函数互相关的红移的约束；和剪切比（SR），这些剪切比从小尺度上的星系剪切相关函数的比率上提供了限制。最后，我们描述了如何合并这些独立的探针以产生封装我们的全部不确定性的红移分布的集合。我们用$σ_ {\ langle z \ rangle} \ sim 0.01 $的$σ_ {\ langle z \ rangle} \ sim 0.01 $的有效不确定性校准红移。
Determining the distribution of redshifts of galaxies observed by wide-field photometric experiments like the Dark Energy Survey is an essential component to mapping the matter density field with gravitational lensing. In this work we describe the methods used to assign individual weak lensing source galaxies from the Dark Energy Survey Year 3 Weak Lensing Source Catalogue to four tomographic bins and to estimate the redshift distributions in these bins. As the first application of these methods to data, we validate that the assumptions made apply to the DES Y3 weak lensing source galaxies and develop a full treatment of systematic uncertainties. Our method consists of combining information from three independent likelihood functions: Self-Organizing Map $p(z)$ (SOMPZ), a method for constraining redshifts from galaxy photometry; clustering redshifts (WZ), constraints on redshifts from cross-correlations of galaxy density functions; and shear ratios (SR), which provide constraints on redshifts from the ratios of the galaxy-shear correlation functions at small scales. Finally, we describe how these independent probes are combined to yield an ensemble of redshift distributions encapsulating our full uncertainty. We calibrate redshifts with combined effective uncertainties of $σ_{\langle z \rangle}\sim 0.01$ on the mean redshift in each tomographic bin.
