The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications
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 (MWA) and the Precision Array for Probing the Epoch of Reionization (PAPER), HERA is a hexagonal array of large (14 m diameter) dishes with suspended dipole feeds. Not only does the dish determine overall sensitivity, it 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. We focus in this paper 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^2 in the optimal dish/feed configuration, implying 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. Lastly we study the impact of these beam measurements on the distribution of foregrounds in Fourier space.
Keywords
Cite
@article{arxiv.1602.03887,
title = {The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications},
author = {Abraham R. Neben and Richard F. Bradley and Jacqueline N. Hewitt and David R. DeBoer and Aaron R. Parsons and James E. Aguirre and Zaki S. Ali and Carina Cheng and Aaron Ewall-Wice and Nipanjana Patra and Nithyanandan Thyagarajan and Judd Bowman and Roger Dickenson and Joshua S. Dillon and Phillip Doolittle and Dennis Egan and Mike Hedrick and Daniel C. Jacobs and Saul A. Kohn and Patricia J. Klima and Kavilan Moodley and Benjamin R. B. Saliwanchik and Patrick Schaffner and John Shelton and H. A. Taylor and Rusty Taylor and Max Tegmark and Butch Wirt and Haoxuan Zheng},
journal= {arXiv preprint arXiv:1602.03887},
year = {2016}
}
Comments
13 pages, 9 figures. Replaced to match accepted ApJ version