论文标题
使用前端极化调制以多个频率观测中CMB观测的长时间稳定性
Long-Timescale Stability in CMB Observations at Multiple Frequencies using Front-End Polarization Modulation
论文作者
论文摘要
宇宙学大尺度测量师（类）是一个望远镜阵列，在以40、90、150和220 GHz为中心的频带上观察宇宙微波背景（CMB）。类测量最大角度尺度上的CMB极化，以限制通货膨胀张量与尺度比率和由于电离引起的光学深度。为了实现从地面进行测量所需的长时间稳定性，Class在每个望远镜上使用前端，可变的偏光调制器。在这里，我们报告了使用所有四个类频率中的数据改善前端调制提供的稳定性的改善。在2021年的一个月调制线性极化数据中，对于40、90、150、150和220 GHz观察带，班级实现了9.1、29.1、20.4和36.4 MHz的膝关节频率。膝关节频率大约比通过分配对正交检测器对实现的数量级低，而无需调节。
The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array observing the Cosmic Microwave Background (CMB) at frequency bands centered near 40, 90, 150, and 220 GHz. CLASS measures the CMB polarization on the largest angular scales to constrain the inflationary tensor-to-scalar ratio and the optical depth due to reionization. To achieve the long time-scale stability necessary for this measurement from the ground, CLASS utilizes a front-end, variable-delay polarization modulator on each telescope. Here we report on the improvements in stability afforded by front-end modulation using data across all four CLASS frequencies. Across one month of modulated linear polarization data in 2021, CLASS achieved median knee frequencies of 9.1, 29.1, 20.4, and 36.4 mHz for the 40, 90, 150, and 220 GHz observing bands. The knee frequencies are approximately an order of magnitude lower than achieved via CLASS pair-differencing orthogonal detector pairs without modulation.
