Erratum: calibration and 21-cm power spectrum estimation in the presence of antenna beam variations
Erratum: calibration and 21-cm power spectrum estimation in the presence of antenna beam variations
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勘误表：存在天线波束变化时的校准和 21 厘米功率谱估计
DOI：
10.1093/mnras/stz3375
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发表时间：
2019
影响因子：
4.8
通讯作者：
A. Nasirudin
中科院分区：
文献类型：
--
作者：
R. Joseph;C. Trott;R. Wayth;A. Nasirudin
探测来自再电离时代（EoR）的信号需要对银河系和星系外前景、低频无线电仪器、仪器校准和数据分析管道有细致的了解。在这项工作中，我们以现有的工作为基础，旨在了解校准误差对21厘米功率谱（PS）测量的影响。校准误差有可能通过引入额外的光谱特征来模拟EoR信号的结构，从而抑制EoR检测。我们提出了一种直接的方法来估计EoR PS估计中各种建模残差的影响。我们将该框架应用于默奇森宽场阵列（MWA）中偶极子破碎的具体情况，以了解其影响并估计其对PS估计的影响。结合估计至少有一个破偶极子的MWA瓦的百分比（15 - 40%）和由这种偶极子引起的光束误差的分析描述，我们计算了校准和源减去后前景的残差。我们发现不正确的光束建模在2D-PS中引入了$\sim 10^3\, \ mathm {mK}^2 \, h^{-3}\, \ mathm {Mpc}^{3}$数量级的偏置。虽然这比目前的最低限度低三个数量级，但比预期信号高两个数量级。因此，确定电流波束模型和方向相关校准管道的精度对于寻找提高采收率信号至关重要。
Detecting a signal from the Epoch of Reionization (EoR) requires an exquisite understanding of Galactic and extragalactic foregrounds, low-frequency radio instruments, instrumental calibration, and data analysis pipelines. In this work, we build upon existing work that aims to understand the impact of calibration errors on 21-cm power spectrum (PS) measurements. It is well established that calibration errors have the potential to inhibit EoR detections by introducing additional spectral features that mimic the structure of EoR signals. We present a straightforward way to estimate the impact of a wide variety of modelling residuals in EoR PS estimation. We apply this framework to the specific case of broken dipoles in Murchison Widefield Array (MWA) to understand its effect and estimate its impact on PS estimation. Combining an estimate of the percentage of MWA tiles that have at least one broken dipole (15–40 per cent) with an analytic description of beam errors induced by such dipoles, we compute the residuals of the foregrounds after calibration and source subtraction. We find that that incorrect beam modelling introduces bias in the 2D-PS on the order of $\sim 10^3\, \mathrm{mK}^2 \, h^{-3}\, \mathrm{Mpc}^{3}$. Although this is three orders of magnitude lower than current lowest limits, it is two orders of magnitude higher than the expected signal. Determining the accuracy of both current beam models and direction-dependent calibration pipelines is therefore crucial in our search for an EoR signal.
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DOI：
10.3847/1538-4357/ab40a8
发表时间：
2019-09
期刊：
The Astrophysical Journal
影响因子：
--
作者：
N. Barry;M. Wilensky;C. Trott;B. Pindor;A. Beardsley;B. Hazelton;I. Sullivan;M. Morales;J. Pober;J. Line;B. Greig;R. Byrne;A. Lanman;W. Li;C. Jordan;R. Joseph;B. McKinley;M. Rahimi;S. Yoshiura;J. Bowman;B. Gaensler;J. Hewitt;D. Jacobs;D. Mitchell;N. Udaya Shankar;S. Sethi;R. Subrahmanyan;S. Tingay;R. Webster;J. Wyithe
通讯作者：
N. Barry;M. Wilensky;C. Trott;B. Pindor;A. Beardsley;B. Hazelton;I. Sullivan;M. Morales;J. Pober;J. Line;B. Greig;R. Byrne;A. Lanman;W. Li;C. Jordan;R. Joseph;B. McKinley;M. Rahimi;S. Yoshiura;J. Bowman;B. Gaensler;J. Hewitt;D. Jacobs;D. Mitchell;N. Udaya Shankar;S. Sethi;R. Subrahmanyan;S. Tingay;R. Webster;J. Wyithe
影响因子：
6.3
作者：
N. Barry;A. Beardsley;R. Byrne;B. Hazelton;M. Morales;J. Pober;I. Sullivan
通讯作者：
N. Barry;A. Beardsley;R. Byrne;B. Hazelton;M. Morales;J. Pober;I. Sullivan
影响因子：
4.8
作者：
Naomi Orosz;J. Dillon;A. Ewall-Wice;A. Parsons;N. Thyagarajan
通讯作者：
Naomi Orosz;J. Dillon;A. Ewall-Wice;A. Parsons;N. Thyagarajan
DOI：
10.3847/1538-4357/ab107d
发表时间：
2018-11
期刊：
The Astrophysical Journal
影响因子：
--
作者：
R. Byrne;M. Morales;B. Hazelton;Wenyang Li;N. Barry;A. Beardsley;R. Joseph;J. Pober;I. Sullivan;C. Trott
通讯作者：
R. Byrne;M. Morales;B. Hazelton;Wenyang Li;N. Barry;A. Beardsley;R. Joseph;J. Pober;I. Sullivan;C. Trott
影响因子：
6.5
作者：
van Haarlem, M. P.;Wise, M. W.;van Zwieten, J.
通讯作者：
van Zwieten, J.