第三代小口径地面微波望远镜的透镜重构  

Lensing reconstruction in the third generation of ground-based small aperture cosmic microwave background telescope

作　　者：刘晋弋 韩嘉康 胡彬 LIU JinYi;HAN JiaKang;HU Bin(Department of Astronomy,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京师范大学天文系,北京100875

出　　处：《中国科学：物理学、力学、天文学》2022年第6期130-137,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家重点研发计划(编号:2020YFC2201603);国家自然科学基金(编号:11653003)资助项目。

摘　　要：本文围绕第三代小口径地面微波望远镜展开了透镜重构算法和数据管线开发的介绍,并给出了相应望远镜参数指标下的透镜重构信噪比分析.我们选取了一个既具有代表性又较为简单的望远镜模型,即:3600平方度天区大小,中等噪声水平(~10μK.arcmin左右)以及中等角分辨率(波束图半高全宽10 arcmin).透镜重构方法,我们采取了技术上较为成熟的透镜“二次估计器”,分别讨论了“温度”估计器、“极化”估计器和“最小方差”估计器.在该算法的框架下,我们开发了端到端的模拟和数据分析管线.借助于该管线,发现当统计噪声在17μK.arcmin的水平上时,透镜的“极化”估计器的噪声要高于“温度”估计器;但是当统计噪声降低到10μK.arcmin时,结果与前者恰好相反.此外,当我们将温度和极化模式的数据加权平均之后,“最小方差”估计器可以在10μK.arcmin噪声水平上,给出信噪比为17的透镜功率谱重构结果.We introduce the lensing reconstruction algorithm and the corresponding pipeline construction of the third generation of the ground-based small aperture cosmic microwave background(CMB)experiment.We assume a characteristic and simplified telescope model,namely 3600 degree square sky coverage,media noise level(~10μK.arcmin)and media angular resolution(beam size 10 arcmin).We adopt the technically mature quadratic estimator and study the reconstruction ability of the T-only,P-only,and the minimal-variance estimator.Using the framework of the quadratic estimators,we developed our lensing reconstruction pipeline.We find,at the 17μK.arcmin noise level,the reconstruction noise of the P-only estimator is worse than that of the T-only estimator.When we upgrade into the 10μK.arcmin noise level case,the results are reversed.Furthermore,when we combine the temperature and polarization modes together,the minimalvariance estimator can reach the signal-to-noise ratio of 17 with the 10μK.arcmin noise setup.

关 键 词：宇宙微波背景辐射 引力透镜 宇宙学 

分 类 号：P111[天文地球—天文学]