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arXiv · 2005.12174

Measuring HERA's primary beam in-situ: methodology and first results

Chuneeta D. Nunhokee·Aaron R. Parsons·Nicholas S. Kern·Bojan Nikolic·Jonathan C. Pober·Gianni Bernardi·Chris L. Carilli·Zara Abdurashidova·James E. Aguirre·Paul Alexander·Zaki S. Ali·Yanga Balfour·Adam P. Beardsley·Tashalee S. Billings·Judd D. Bowman·Richard F. Bradley·Jacob Burba·Carina Cheng·David R. DeBoer·Matt Dexter·Eloy de~Lera~Acedo·Joshua S. Dillon·Aaron Ewall-Wice·Nicolas Fagnoni·Randall Fritz·Steve R. Furlanetto·Kingsley Gale-Sides·Brian Glendenning·Deepthi Gorthi·Bradley Greig·Jasper Grobbelaar·Ziyaad Halday·Bryna J. Hazelton·Jacqueline N. Hewitt·Daniel C. Jacobs·Austin Julius·Joshua Kerrigan·Piyanat Kittiwisit·Saul A. Kohn·Matthew Kolopanis·Adam Lanman·Paul La~Plante·Telalo Lekalake·Adrian Liu·David MacMahon·Lourence Malan·Cresshim Malgas·Matthys Maree·Zachary E. Martinot·Eunice Matsetela·Andrei Mesinger·Mathakane Molewa·Miguel F. Morales·Tshegofalang Mosiane·Abraham R. Neben·Nipanjana Patra·Samantha Pieterse·Nima Razavi-Ghods·Jon Ringuette·James Robnett·Kathryn Rosie·Peter Sims·Craig Smith·Angelo Syce·Nithyanandan Thyagarajan·Peter K. ~G. Williams·Haoxuan Zheng
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Abstract

The central challenge in 21~cm cosmology is isolating the cosmological signal from bright foregrounds. Many separation techniques rely on the accurate knowledge of the sky and the instrumental response, including the antenna primary beam. For drift-scan telescopes such as the Hydrogen Epoch of Reionization Array \citep[HERA, ][]{DeBoer2017} that do not move, primary beam characterization is particularly challenging because standard beam-calibration routines do not apply \citep{Cornwell2005} and current techniques require accurate source catalogs at the telescope resolution. We present an extension of the method from \citet{Pober2012} where they use beam symmetries to create a network of overlapping source tracks that break the degeneracy between source flux density and beam response and allow their simultaneous estimation. We fit the beam response of our instrument using early HERA observations and find that our results agree well with electromagnetic simulations down to a -20~dB level in power relative to peak gain for sources with high signal-to-noise ratio. In addition, we construct a source catalog with 90 sources down to a flux density of 1.4~Jy at 151~MHz.

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Chuneeta D. Nunhokee, Aaron R. Parsons, Nicholas S. Kern, Bojan Nikolic, Jonathan C. Pober, Gianni Bernardi, Chris L. Carilli, Zara Abdurashidova, James E. Aguirre, Paul Alexander, Zaki S. Ali, Yanga Balfour, Adam P. Beardsley, Tashalee S. Billings, Judd D. Bowman, Richard F. Bradley, Jacob Burba, Carina Cheng, David R. DeBoer, Matt Dexter, Eloy de~Lera~Acedo, Joshua S. Dillon, Aaron Ewall-Wice, Nicolas Fagnoni, Randall Fritz, Steve R. Furlanetto, Kingsley Gale-Sides, Brian Glendenning, Deepthi Gorthi, Bradley Greig, Jasper Grobbelaar, Ziyaad Halday, Bryna J. Hazelton, Jacqueline N. Hewitt, Daniel C. Jacobs, Austin Julius, Joshua Kerrigan, Piyanat Kittiwisit, Saul A. Kohn, Matthew Kolopanis, Adam Lanman, Paul La~Plante, Telalo Lekalake, Adrian Liu, David MacMahon, Lourence Malan, Cresshim Malgas, Matthys Maree, Zachary E. Martinot, Eunice Matsetela, Andrei Mesinger, Mathakane Molewa, Miguel F. Morales, Tshegofalang Mosiane, Abraham R. Neben, Nipanjana Patra, Samantha Pieterse, Nima Razavi-Ghods, Jon Ringuette, James Robnett, Kathryn Rosie, Peter Sims, Craig Smith, Angelo Syce, Nithyanandan Thyagarajan, Peter K. ~G. Williams, Haoxuan Zheng. 2020-05-25. Measuring HERA's primary beam in-situ: methodology and first results. https://doi.org/10.3847/1538-4357/ab9634

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