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arXiv 2101.06338astro-ph.IM
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HIRAX Radio Telescope的机械和光学设计

Mechanical and Optical Design of the HIRAX Radio Telescope

Benjamin R. B. Saliwanchik, Aaron Ewall-Wice, Devin Crichton, Emily R. Kuhn, Deniz Ölçek, Kevin Bandura, Martin Bucher, Tzu-Ching Chang, H. Cynthia Chiang, Kit … 展开作者

Benjamin R. B. Saliwanchik, Aaron Ewall-Wice, Devin Crichton, Emily R. Kuhn, Deniz Ölçek, Kevin Bandura, Martin Bucher, Tzu-Ching Chang, H. Cynthia Chiang, Kit Gerodias, Kabelo Kesebonye, Vincent MacKay, Kavilan Moodley, Laura B. Newburgh, Viraj Nistane, Jeffrey B. Peterson, Elizabeth Pieters, Carla Pieterse, Keith Vanderlinde, Jonathan L. Sievers, Amanda Weltman, Dallas Wulf

摘要:

氢强度和实时分析实验(HIRAX)是一个计划中的干涉射电望远镜阵列,最终将由1024个紧密包装的6米碟形天线组成,将部署在SKA南非站点。HIRAX将利用中性氢的21厘米超精细跃迁对南部天空的大部分进行调查,以测量重子声学振荡(BAO)。它将在400-800 MHz之间工作,分辨率为391 kHz,对应的红移范围为$0.8 < z < 2.5$,最小值$Δz/z$约为0.003。HIRAX的主要科学目标之一是通过测量在宇宙学显著范围内作为红移函数的BAO尺度来约束暗能量状态方程。实现这一目标的地方严格要求的机械和光学设计的HIRAX仪器,本文所述。这包括用于优化仪器的模拟,包括碟形焦比、接收器支撑机制和仪器布线。作为这些模拟的结果,抛物面焦比已被减小到0.23,以减少抛物面间串扰,馈源支撑机构已被重新设计为宽(35厘米直径)。中心柱,并且馈电设计已经被修改,以允许接收器的布线直接沿着馈电和碟形天线的对称轴线通过,以消除波束不对称并减小旁瓣幅度。来自这些全仪器模拟的光束也用于天体物理m模式分析管道,该管道用于评估宇宙学约束并确定由于阵列元件的物理非冗余而导致的潜在系统污染。这种端到端的仿真管道用于通知盘制造和组装规范,这将指导第一级HIRAX 256元件阵列的生产和构造。

英文摘要:

The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a planned interferometric radio telescope array that will ultimately consist of 1024 close packed 6 m dishes that will be deployed at the SKA South Africa site. HIRAX will survey the majority of the southern sky to measure baryon acoustic oscillations (BAO) using the 21 cm hyperfine transition of neutral hydrogen. It will operate between 400-800 MHz with 391 kHz resolution, corresponding to a redshift range of $0.8 < z < 2.5$ and a minimum $Δz/z$ of ~0.003. One of the primary science goals of HIRAX is to constrain the dark energy equation of state by measuring the BAO scale as a function of redshift over a cosmologically significant range. Achieving this goal places stringent requirements on the mechanical and optical design of the HIRAX instrument which are described in this paper. This includes the simulations used to optimize the instrument, including the dish focal ratio, receiver support mechanism, and instrument cabling. As a result of these simulations, the dish focal ratio has been reduced to 0.23 to reduce inter-dish crosstalk, the feed support mechanism has been redesigned as a wide (35 cm diam.) central column, and the feed design has been modified to allow the cabling for the receiver to pass directly along the symmetry axis of the feed and dish in order to eliminate beam asymmetries and reduce sidelobe amplitudes. The beams from these full-instrument simulations are also used in an astrophysical m-mode analysis pipeline which is used to evaluate cosmological constraints and determine potential systematic contamination due to physical non-redundancies of the array elements. This end-to-end simulation pipeline was used to inform the dish manufacturing and assembly specifications which will guide the production and construction of the first-stage HIRAX 256-element array.

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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