The Hydrogen Epoch of Reionization Array Dish. I. Beam Pattern Measurements and Science Implications
Name
Neben-2016-The hydrogen epoch o.pdf
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4.37 MB
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Author(s)
Bradley, Richard F.
DeBoer, David R.
Parsons, Aaron R.
Aguirre, James E.
Ali, Zaki S.
Cheng, Carina
Patra, Nipanjana
Thyagarajan, Nithyanandan
Bowman, Judd
Dickenson, Roger
Date Issued
August 2016
Journal
The Astrophysical Journal
Publisher
IOP Publishing
Citation
Neben, Abraham R. et al. “The Hydrogen Epoch of Reionization Array Dish. I. Beam Pattern Measurements and Science Implications.” The Astrophysical Journal 826.2 (2016): 199. © 2016 The American Astronomical Society
Version
Final published version
Abstract
The Hydrogen Epoch of Reionization Array (HERA) is a radio interferometer aiming to detect the power spectrum of 21 cm fluctuations from neutral hydrogen from the epoch of reionization (EOR). Drawing on lessons from the Murchison Widefield Array and the Precision Array for Probing the EOR, HERA is a hexagonal array of large (14 m diameter) dishes with suspended dipole feeds. The dish not only determines overall sensitivity, but also affects the observed frequency structure of foregrounds in the interferometer. This is the first of a series of four papers characterizing the frequency and angular response of the dish with simulations and measurements. In this paper, we focus on the angular response (i.e., power pattern), which sets the relative weighting between sky regions of high and low delay and thus apparent source frequency structure. We measure the angular response at 137 MHz using the ORBCOMM beam mapping system of Neben et al. We measure a collecting area of 93 m[superscript 2] in the optimal dish/feed configuration, implying that HERA-320 should detect the EOR power spectrum at z ∼ 9 with a signal-to-noise ratio of 12.7 using a foreground avoidance approach with a single season of observations and 74.3 using a foreground subtraction approach. Finally, we study the impact of these beam measurements on the distribution of foregrounds in Fourier space.
MIT Department
Massachusetts Institute of Technology. Department of Physics
MIT Kavli Institute for Astrophysics and Space Research
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DOI of Published Version
https://doi.org/10.3847/0004-637X/826/2/199
