Journal article
BEAM-FORMING ERRORS in MURCHISON WIDEFIELD ARRAY PHASED ARRAY ANTENNAS and THEIR EFFECTS on EPOCH of REIONIZATION SCIENCE
AR Neben, JN Hewitt, RF Bradley, JS Dillon, G Bernardi, JD Bowman, F Briggs, RJ Cappallo, BE Corey, AA Deshpande, R Goeke, LJ Greenhill, BJ Hazelton, M Johnston-Hollitt, DL Kaplan, CJ Lonsdale, SR McWhirter, DA Mitchell, MF Morales, E Morgan Show all
Astrophysical Journal | Published : 2016
Abstract
Accurate antenna beam models are critical for radio observations aiming to isolate the redshifted 21 cm spectral line emission from the Dark Ages and the Epoch of Reionization (EOR) and unlock the scientific potential of 21 cm cosmology. Past work has focused on characterizing mean antenna beam models using either satellite signals or astronomical sources as calibrators, but antenna-to-antenna variation due to imperfect instrumentation has remained unexplored. We characterize this variation for the Murchison Widefield Array (MWA) through laboratory measurements and simulations, finding typical deviations of the order of ±10%-20% near the edges of the main lobe and in the sidelobes. We consid..
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Grants
Awarded by National Science Foundation
Funding Acknowledgements
This work was supported by NSF grant AST-0821321, the Marble Astrophysics Fund, and the MIT School of Science. We thank Aaron Ewall-Wice and Hamdi Mani for assistance in running these experiments, Steve Burns for debugging beam-former issues, and Danny Jacobs, Nithyanandan Thyagarajan, and Lu Feng for helpful discussions.r This scientific work makes use of the Murchison Radio-astronomy Observatory, operated by CSIRO. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. Support for the MWA comes from the U.S. National Science Foundation (grants AST-0457585, PHY-0835713, CAREER-0847753, and AST-0908884), the Australian Research Council (LIEF grants LE0775621 and LE0882938), the U.S. Air Force Office of Scientific Research (grant FA9550-0510247), and the Centre for All-sky Astrophysics (an Australian Research Council Centre of Excellence funded by grant CE110001020). Support is also provided by the Smithsonian Astrophysical Observatory, the MIT School of Science, the Raman Research Institute, the Australian National University, and the Victoria University of Wellington (via grant MED-E1799 from the New Zealand Ministry of Economic Development and an IBM Shared University Research Grant). The Australian Federal government provides additional support via the Commonwealth Scientific and Industrial Research Organisation (CSIRO), National Collaborative Research Infrastructure Strategy, Education Investment Fund, and the Australia India Strategic Research Fund, and Astronomy Australia Limited, under contract to Curtin University. We acknowledge the iVEC Petabyte Data Store, the Initiative in Innovative Computing and the CUDA Center for Excellence sponsored by NVIDIA at Harvard University, and the International Centre for Radio Astronomy Research (ICRAR), a Joint Venture of Curtin University and The University of Western Australia, funded by the Western Australian State government.