利用默奇森宽场阵列对再电离时期的网格化与直接双谱估计
宇宙学与河外天体物理
2019-07-24 v1 天体物理仪器与方法
摘要
我们应用两种方法，从默奇森宽场阵列（MWA）再电离时期（EoR）项目所采数据中估计21 cm双谱。使用Phase II紧凑阵列获取的数据，可直接对多组冗余间隔的天线瓦片三角形进行双谱估计，也可基于网格化至平面的数据进行估计。我们将直接与网格化双谱估计器应用于2016与2017观测季的21小时高频段（167–197 MHz；=6.2–7.5）数据。推导了点源前景双谱偏差与方差的解析预测。我们比较了这些方法的输出、前景对信号的贡献，以及未来用冗余与非冗余阵列测量双谱的前景。我们发现，某些三角形构型在10小时后给出的双谱估计与预期噪声水平一致，而等边构型则受前景强烈主导。可谨慎选择三角形构型以降低阻碍功率谱估计器的前景偏差，且对某些波模，21 cm双谱可能在比21 cm功率谱更短的时间内被探测到，仅需数百小时即可探测。
引用
@article{arxiv.1905.07161,
title = {Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array},
author = {Cathryn M. Trott and Catherine A. Watkinson and Christopher H. Jordan and Shintaro Yoshiura and Suman Majumdar and N. Barry and R. Byrne and B. J. Hazelton and K. Hasegawa and R. Joseph and T. Kaneuji and K. Kubota and W. Li and J. Line and C. Lynch and B. McKinley and D. A. Mitchell and M. F. Morales and S. Murray and B. Pindor and J. C. Pober and M. Rahimi and J. Riding and K. Takahashi and S. J. Tingay and R. B. Wayth and R. L. Webster and M. Wilensky and J. S. B. Wyithe and Q. Zheng and David Emrich and A. P. Beardsley and T. Booler and B. Crosse and T. M. O. Franzen and L. Horsley and M. Johnston-Hollitt and D. L. Kaplan and D. Kenney and D. Pallot and G. Sleap and K. Steele and M. Walker and A. Williams and C. Wu},
journal= {arXiv preprint arXiv:1905.07161},
year = {2019}
}
备注
19 pages, 10 figures, accepted for publication in PASA