Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
复制标题
通过仿真了解 HERA 第一阶段接收器系统及其对 EoR 延迟功率谱可检测性的影响
DOI：
10.1093/mnras/staa3268
复制
发表时间：
2020
影响因子：
4.8
通讯作者：
Bernardi, Gianni
中科院分区：
文献类型：
--
作者：
Fagnoni, Nicolas;de Lera Acedo, Eloy;DeBoer, David R;Abdurashidova, Zara;Aguirre, James E;Alexander, Paul;Ali, Zaki S;Balfour, Yanga;Beardsley, Adam P;Bernardi, Gianni
用前景避免法检测再电离(EOR)延迟功率谱高度依赖于仪器的色度。射电望远镜引起的系统效应将前景信号扩展到延迟域，污染了理论上可观察到的提高采收率窗口。应用于再电离阵列(HERA)的氢纪元，本文结合了详细的电磁和电学模拟，以模拟仪器的色度效应，并量化其频率和时间响应。特别是，模拟接收器、传输电缆和互耦合的影响也被包括在内。这些模拟能够准确地预测连接天线和后端的150米电缆中发生的反射强度。它们还表明，由于相互耦合，电磁波可以通过阵列的大段从一个碟子传播到另一个碟子。在取决于阵列大小和天线位置的特征延迟之后，模拟的系统时间响应衰减因数104。最终，由于电缆中的反射，系统响应在1400秒后衰减了105倍，这对应于150兆赫兹下0.7以上的特征∥模式。因此，这项新的研究表明，HERA第一阶段提高采收率信号的检测将比预期的更具挑战性。另一方面，它提高了我们对望远镜的理解，这对于减少仪器的色度是必不可少的。
The detection of the Epoch of Reionization (EoR) delay power spectrum using a ‘foreground avoidance method’ highly depends on the instrument chromaticity. The systematic effects induced by the radio telescope spread the foreground signal in the delay domain, which contaminates the EoR window theoretically observable. Applied to the Hydrogen Epoch of Reionization Array (HERA), this paper combines detailed electromagnetic and electrical simulations in order to model the chromatic effects of the instrument, and quantify its frequency and time responses. In particular, the effects of the analogue receiver, transmission cables, and mutual coupling are included. These simulations are able to accurately predict the intensity of the reflections occurring in the 150-m cable which links the antenna to the backend. They also show that electromagnetic waves can propagate from one dish to another one through large sections of the array due to mutual coupling. The simulated system time response is attenuated by a factor 104after a characteristic delay which depends on the size of the array and on the antenna position. Ultimately, the system response is attenuated by a factor 105after 1400 ns because of the reflections in the cable, which corresponds to characterizablek∥-modes above 0.7at 150 MHz. Thus, this new study shows that the detection of the EoR signal with HERA Phase I will be more challenging than expected. On the other hand, it improves our understanding of the telescope, which is essential to mitigate the instrument chromaticity.
登录
查看更多内容
原位测量 HERA 主光束：方法和初步结果
DOI：
10.3847/1538-4357/ab9634
发表时间：
2020
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Nunhokee, Chuneeta D.;Parsons, Aaron R.;Kern, Nicholas S.;Nikolic, Bojan;Pober, Jonathan C.;Bernardi, Gianni;Carilli, Chris L.;Abdurashidova, Zara;Aguirre, James E.;Alexander, Paul
通讯作者：
Alexander, Paul
再电离阵列氢历元的绝对标定策略及其对 21 cm 功率谱的影响
DOI：
10.3847/1538-4357/ab67bc
发表时间：
2020
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Kern, Nicholas S.;Dillon, Joshua S.;Parsons, Aaron R.;Carilli, Christopher L.;Bernardi, Gianni;Abdurashidova, Zara;Aguirre, James E.;Alexander, Paul;Ali, Zaki S.;Balfour, Yanga
通讯作者：
Balfour, Yanga
DOI：
10.3847/0004-637x/825/1/9
发表时间：
2016-03
期刊：
The Astrophysical Journal
影响因子：
--
作者：
N. Thyagarajan;A. Parsons;D. DeBoer;J. Bowman;A. Ewall-Wice;A. Neben;Nipanjana Patra
通讯作者：
N. Thyagarajan;A. Parsons;D. DeBoer;J. Bowman;A. Ewall-Wice;A. Neben;Nipanjana Patra
DOI：
10.3847/0004-637x/831/2/196
发表时间：
2016-02
期刊：
The Astrophysical Journal
影响因子：
--
作者：
A. Ewall-Wice;R. Bradley;R. Bradley;D. DeBoer;J. Hewitt;A. Parsons;J. Aguirre;Z. Ali;J. Bowman;Carina Cheng;A. Neben;Nipanjana Patra;N. Thyagarajan;M. Venter;E. D. L. Acedo;J. Dillon;R. Dickenson;P. Doolittle;D. Egan;Mike Hedrick;P. Klima;S. Kohn;Patrick Schaffner;J. Shelton;B. Saliwanchik;H. Taylor;R. Taylor;M. Tegmark;B. Wirt
通讯作者：
A. Ewall-Wice;R. Bradley;R. Bradley;D. DeBoer;J. Hewitt;A. Parsons;J. Aguirre;Z. Ali;J. Bowman;Carina Cheng;A. Neben;Nipanjana Patra;N. Thyagarajan;M. Venter;E. D. L. Acedo;J. Dillon;R. Dickenson;P. Doolittle;D. Egan;Mike Hedrick;P. Klima;S. Kohn;Patrick Schaffner;J. Shelton;B. Saliwanchik;H. Taylor;R. Taylor;M. Tegmark;B. Wirt
影响因子：
20.6
作者：
HARRIS, FJ
通讯作者：
HARRIS, FJ