HERA-19 调试阵列：方向相关效应
天体物理仪器与方法
2019-09-11 v2
摘要
前景功率主导了那些寻求再电离纪元(EoR)中高红移 HI 发射统计探测的干涉仪的测量。仪器的色散性在频率的傅里叶变换（正比于 ）中创造了边界，一边是光谱平滑的发射（强同步辐射前景的特征，即“楔型区”），另一边是来自 EoR 中 HI 的光谱结构发射（即“EoR 窗口”）。法拉第旋转可将光谱结构注入原本平滑的偏振前景发射中，通过仪器效应或错误定标可能污染 EoR 窗口。利用 HERA 19 单元调试阵列的数据，我们在功率谱域研究了这台新仪器的偏振响应。我们基于全局天空模型的非偏振弥漫发射进行了简单的基于图像的定标，并表明其在阵列的名义冗余基线上实现了定性冗余以及合理的幅度精度。我们构建了所有全偏振相干量在所有伪斯托克斯参数中的功率谱。我们与基于非偏振弥漫天空模型以及碟形天线和馈源的详细电磁模拟的仿真进行比较，确认在斯托克斯 I 中，定标未引入超出预期水平的显著光谱结构。此外，该定标在考虑的 8 天观测中保持稳定。在线性偏振斯托克斯参数的功率谱中观察到超出功率，其不易归因于通过主波束的泄漏，而是源于残余定标误差与实际偏振发射的某种组合。发现斯托克斯 V 与零功率的期望高度不符，强烈指向需要更精确的偏振定标。
引用
@article{arxiv.1802.04151,
title = {The HERA-19 Commissioning Array: Direction Dependent Effects},
author = {Saul A. Kohn and James E. Aguirre and Paul La Plante and Tashalee S. Billings and Paul M. Chichura and Austin F. Fortino and Amy S. Igarashi and Roshan K. Benefo and Samavarti Gallardo and Zachary E. Martinot and Chuneeta D. Nunhokee and Nicholas S. Kern and Philip Bull and Adrian Liu and Paul Alexander and Zaki S. Ali and Adam P. Beardsley and Gianni Bernardi and Judd D. Bowman and Richard F. Bradley and Chris L. Carilli and Carina Cheng and David R. DeBoer and Eloy de Lera Acedo and Joshua S. Dillon and Aaron Ewall-Wice and Gcobisa Fadana and Nicolas Fagnoni and Randall Fritz and Steven R. Furlanetto and Brian Glendenning and Bradley Greig and Jasper Grobbelaar and Bryna J. Hazelton and Jacqueline N. Hewitt and Jack Hickish and Daniel C. Jacobs and Austin Julius and MacCalvin Kariseb and Matthew Kolopanis and Telalo Lekalake and Anita Loots and David MacMahon and Lourence Malan and Cresshim Malgas and Matthys Maree and Nathan Mathison and Eunice Matsetela and Andrei Mesinger and Miguel F. Morales and Abraham R. Neben and Bojan Nikolic and Aaron R. Parsons and Nipanjana Patra 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 Nithyanandan Thyagarajan and Peter K. G. Williams and Haoxuan Zheng},
journal= {arXiv preprint arXiv:1802.04151},
year = {2019}
}
备注
21 pages, 12 figures, submitted to ApJ