arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.05946astro-ph.IMastro-ph.CO
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天籁碟形探路者天线阵:原型transit无线电干涉仪的设计、操作和性能

The Tianlai Dish Pathfinder Array: design, operation and performance of a prototype transit radio interferometer

Fengquan Wu, Jixia Li, Shifan Zuo, Xuelei Chen, Santanu Das, John P. Marriner, Trevor M. Oxholm, Anh Phan, Albert Stebbins, Peter T. Timbie, Reza Ansari, Jean-E… 展开作者

Fengquan Wu, Jixia Li, Shifan Zuo, Xuelei Chen, Santanu Das, John P. Marriner, Trevor M. Oxholm, Anh Phan, Albert Stebbins, Peter T. Timbie, Reza Ansari, Jean-Eric Campagne, Zhiping Chen, Yanping Cong, Qizhi Huang, Yichao Li, Tao Liu, Yingfeng Liu, Chenhui Niu, Calvin Osinga, Olivier Perdereau, Jeffrey B. Peterson, Huli Shi, Gage Siebert, Shijie Sun, Haijun Tian, Gregory S. Tucker, Qunxiong Wang, Rongli Wang, Yougang Wang, Yanlin Wu, Yidong Xu, Kaifeng Yu, Zijie Yu, Jiao Zhang, Juyong Zhang, Jialu Zhu

摘要:

天籁碟形探路者天线阵是一个射电干涉仪,旨在检验再电离后宇宙21厘米强度测绘技术,作为测量大尺度宇宙结构的手段。它以恒定的速度对天空进行漂移扫描。我们描述了该仪器的设计,校准,噪声水平和稳定性,基于对截至2019年10月的6,200小时天空观测的约$\sim 5 \%$的分析。使用无人机和明亮源的过境确定光束图案是一致的,并与电磁模拟兼容。结合所有的基线,我们在明亮的光源周围绘制地图,并显示阵列的行为与预期一致。在不同的赤纬几百小时的观测已被用来研究阵列的几何形状和指向缺陷,以及仪器的噪声行为。我们表明,系统的温度是低于80 K的大多数馈电天线,和噪声波动减少预期的积分时间,至少高达几百秒。对北天极10个夜晚观测的长积分进行分析,得到振幅为20-30 mK的射电信号,这与$1 ~\mathrm{MHz} \times 1~ \mathrm{min}$装仓时$<10\,$ mK精度的NCP射电天空的预期信号一致。对光谱进行高通滤波以去除平滑光谱信号,在$0.5\,$ mK水平产生与零信号一致的残差。

英文摘要:

The Tianlai Dish Pathfinder Array is a radio interferometer designed to test techniques for 21~cm intensity mapping in the post-reionization universe as a means for measuring large-scale cosmic structure. It performs drift scans of the sky at constant declination. We describe the design, calibration, noise level, and stability of this instrument based on the analysis of about $\sim 5 \%$ of 6,200 hours of on-sky observations through October, 2019. Beam pattern determinations using drones and the transit of bright sources are in good agreement, and compatible with electromagnetic simulations. Combining all the baselines, we make maps around bright sources and show that the array behaves as expected. A few hundred hours of observations at different declinations have been used to study the array geometry and pointing imperfections, as well as the instrument noise behaviour. We show that the system temperature is below 80~K for most feed antennas, and that noise fluctuations decrease as expected with integration time, at least up to a few hundred seconds. Analysis of long integrations, from 10 nights of observations of the North Celestial Pole, yielded visibilities with amplitudes of 20-30~mK, consistent with the expected signal from the NCP radio sky with $<10\,$mK precision for $1 ~\mathrm{MHz} \times 1~ \mathrm{min}$ binning. Hi-pass filtering the spectra to remove smooth spectrum signal yields a residual consistent with zero signal at the $0.5\,$mK level.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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