消除 21 cm 宇宙射电观测中互耦合导致的校准误差
天体物理仪器与方法
2024-07-31 v1 宇宙学与河外天体物理
摘要
中性氢的 21 cm 过渡象征着对原始时代 (EoR) 的最佳观测手段。这推动了低频射电干涉仪阵列（如氢原子原始时代射电阵列(HERA)）的建设，旨在首次系统性地绘制该辐射。然而，21 cm 射电观测需要高精度校准。由于 HERA 阵列的空间紧凑性，易受互耦合影响，导致校准误差呈非平滑特性，污染数据。当使用不光滑的增益进行校准时，本质上光谱平滑的前景辐射开始以不可清晰检测原始时代信号的方式污染数据。本文我们表明，通过在校准前对数据应用自定义时域滤波器，可降低互耦合对校准质量的影响。我们发现，通过这种方式获得的校准解更为稳健，进而减少了观测到的前景功率泄漏。具体而言，我们在 处将前景功率泄漏降低了两个数量级。
引用
@article{arxiv.2407.20923,
title = {Mitigating calibration errors from mutual coupling with time-domain filtering of 21 cm cosmological radio observations},
author = {N. Charles and N. S. Kern and R. Pascua and G. Bernardi and L. Bester and O. Smirnov and E. d. L. Acedo and Z. Abdurashidova and T. Adams and J. E. Aguirre and R. Baartman and A. P. Beardsley and L. M. Berkhout and T. S. Billings and J. D. Bowman and P. Bull and J. Burba and R. Byrne and S. Carey and K. Chen and S. Choudhuri and T. Cox and D. R. DeBoer and M. Dexter and J. S. Dillon and S. Dynes and N. Eksteen and J. Ely and A. Ewall-Wice and R. Fritz and S. R. Furlanetto and K. Gale-Sides and H. Garsden and B. K. Gehlot and A. Ghosh and A. Gorce and D. Gorthi and Z. Halday and B. J. Hazelton and J. N. Hewitt and J. Hickish and T. Huang and D. C. Jacobs and A. Josaitis and J. Kerrigan and P. Kittiwisit and M. Kolopanis and A. Lanman and A. Liu and Y. -Z. Ma and D. H. E. MacMahon and L. Malan and K. Malgas and C. Malgas and B. Marero and Z. E. Martinot and L. McBride and A. Mesinger and N. Mohamed-Hinds and M. Molewa and M. F. Morales and S. Murray and B. Nikolic and H. Nuwegeld and A. R. Parsons and N. Patra and P. L. Plante and Y. Qin and E. Rath and N. Razavi-Ghods and D. Riley and J. Robnett and K. Rosie and M. G. Santos and P. Sims and S. Singh and D. Storer and H. Swarts and J. Tan and M. J. Wilensky and P. K. G. Williams and P. v. Wyngaarden and H. Zheng},
journal= {arXiv preprint arXiv:2407.20923},
year = {2024}
}