使用点源对 SPT-3G 的偏振束响应进行表征
宇宙学与河外天体物理
2026-02-09 v1 天体物理仪器与方法
摘要
精确测量宇宙微波背景偏振需要严格控制仪器系统atics。对于南极望远镜第三代相机 (SPT-3G)，准确的束表征对于理解偏振 mm 波 sky 至关重要。本文采用对 100 个偏振外星点源的观测，直接测量了 SPT-3G 的偏振束响应。以前的 SPT-3G CMB 功率谱分析引入了描述束侧瓣中保留偏振程度的现象学参数 。这些分析发现，为实现不同频率带之间的偏振功率谱一致性，存在显著的偏振消减现象。我们的直接测量结果显示，在 95 GHz 时 ，在 150 GHz 时 ，在 220 GHz 时 ，表明束侧瓣几乎不存在显著的偏振消减。我们通过 extensive 系统性测试验证了这些结果，包括贝叶斯后验抽样与频率主义 bootstrap 抽样、real-space 与 Fourier-space 分析，以及温度到偏振泄漏处理、协方差确定和源选择的variations。与之前从 cosmological 分析中推断的值比较，我们发现 的 mild 张力。然而，这种表面性差异取决于束建模，因为我们的点源基于分析在更高的 multipole 上对 提供了更多约束力。这使得功率谱分析中观察到的频率依赖残差可接受三个解释：统计波动、需要更精细的偏振束模型，或除束偏振消减外的其他 systematics。
引用
@article{arxiv.2602.06334,
title = {Characterization of the Polarization Beam Response of SPT-3G Using Point Sources},
author = {T. de Haan and M. Archipley and N. Huang and A. J. Anderson and B. Ansarinejad and L. Balkenhol and D. R. Barron and K. Benabed and A. N. Bender and B. A. Benson and F. Bianchini and L. E. Bleem and S. Bocquet and F. R. Bouchet and L. Bryant and E. Camphuis and M. G. Campitiello and J. E. Carlstrom and J. Carron and C. L. Chang and P. Chaubal and P. M. Chichura and A. Chokshi and T. -L. Chou and A. Coerver and T. M. Crawford and C. Daley and K. R. Dibert and M. A. Dobbs and M. Doohan and A. Doussot and D. Dutcher and W. Everett and C. Feng and K. R. Ferguson and N. C. Ferree and K. Fichman and A. Foster and S. Galli and A. E. Gambrel and R. W. Gardner and F. Ge and N. Goeckner-Wald and R. Gualtieri and F. Guidi and S. Guns and N. W. Halverson and E. Hivon and A. Y. Q. Ho and G. P. Holder and W. L. Holzapfel and J. C. Hood and A. Hryciuk and F. Keruzore and A. R. Khalife and L. Knox and M. Korman and K. Kornoelje and C. -L. Kuo and K. Levy and Y. Li and A. E. Lowitz and C. Lu and G. P. Lynch and T. J. Maccarone and A. S. Maniyar and E. S. Martsen and F. Menanteau and M. Millea and J. Montgomery and Y. Nakato and T. Natoli and G. I. Noble and Y. Omori and A. Ouellette and Z. Pan and P. Paschos and K. A. Phadke and A. W. Pollak and K. Prabhu and W. Quan and M. Rahimi and A. Rahlin and C. L. Reichardt and M. Rouble and J. E. Ruhl and E. Schiappucci and A. C. Silva Oliveira and A. Simpson and J. A. Sobrin and A. A. Stark and J. Stephen and C. Tandoi and B. Thorne and C. Trendafilova and C. Umilta and J. D. Vieira and A. G. Vieregg and A. Vitrier and Y. Wan and N. Whitehorn and W. L. K. Wu and M. R. Young and J. A. Zebrowski},
journal= {arXiv preprint arXiv:2602.06334},
year = {2026}
}