氢再电离时代阵列天线 III：利用反射测量测定原型单元的角色散特性
天体物理仪器与方法
2018-03-21 v2
摘要
探测来自再电离时代（EoR）的红移 21 cm 信号的实验努力主要受限于是角色散的仪器系统效应。用于 21 cm 功率谱测量的延迟谱方法使人们重新关注天线角色散对该测量可行性的关键影响。该方法建立了仪器时域响应与 21 cm EoR 实验可获取的功率谱模式之间的直接关系。我们检验了目前正在南非卡鲁沙漠观测的氢再电离时代阵列（HERA）阵列单元原型的性能。我们提出了一个数学框架，根据 100-200 MHz 之间的回波损耗测量推导 HERA 原型单元在接收时的波束积分频率响应，并确定了延迟空间中额外前景污染的程度。测量揭示了相较于 HERA 单元模拟研究存在的过量光谱结构。结合在功率谱最优二次估计中引入逆协方差加权的 HERA 数据分析流水线，我们发现尽管其偏离模拟响应，HERA 原型单元仍满足前景衰减极限所提出的必要标准，并有可能在空间模式低至 ~Mpc 处测量功率谱。该工作强调了一种直接测量仪器响应并评估其对未来将使用反射面型天线的 21 cm EoR 功率谱测量影响的简便方法。
引用
@article{arxiv.1701.03209,
title = {The Hydrogen Epoch of Reionization Array Dish III: Measuring Chromaticity of Prototype Element with Reflectometry},
author = {Nipanjana Patra and Aaron R. Parsons and David R. DeBoer and Nithyanandan Thyagarajan and Aaron Ewall-Wice and Gilbert Hsyu and Tsz Kuk Leung and Cherie K. Day and James E. Aguirre and Paul Alexander and Zaki S. Ali and Adam P. Beardsley and Judd D. Bowman and Richard F. Bradley and Chris L. Carilli and Carina Cheng and Eloy de Lera Acedo and Joshua S. Dillon and Gcobisa Fadana and Nicolas Fagnoni and Randall Fritz and Steve R. Furlanetto and Brian Glendenning and Bradley Greig and Jasper Grobbelaar and Bryna J. Hazelton and Jacqueline N. Hewitt and Daniel C. Jacobs and Austin Julius and MacCalvin Kariseb and Saul A. Kohn and Anna Lebedeva and Telalo Lekalake and Adrian Liu and Anita Loots and David MacMahon and Lourence Malan and Cresshim Malgas and Matthys Maree and Zachary Martinot and Nathan Mathison and Eunice Matsetela and Andrei Mesinger and Miguel F. Morales and Abraham R. Neben and Samantha Pieterse and Jonathan C. Pober and Nima Razavi-Ghods and Jon Ringuette and James Robnett and Kathryn Rosie and Raddwine Sell and Craig Smith and Angelo Syce and Max Tegmark and Peter K. G. Williams and Haoxuan Zheng},
journal= {arXiv preprint arXiv:1701.03209},
year = {2018}
}
备注
13 pages, 10 figures, Submitted to APJ