Journal article
Direct Optimal Mapping for 21 cm Cosmology: A Demonstration with the Hydrogen Epoch of Reionization Array
Z Xu, JN Hewitt, KF Chen, H Kim, JS Dillon, NS Kern, MF Morales, BJ Hazelton, R Byrne, N Fagnoni, EDL Acedo, Z Abdurashidova, T Adams, JE Aguirre, P Alexander, ZS Ali, R Baartman, Y Balfour, AP Beardsley, G Bernardi Show all
Astrophysical Journal | Published : 2022
Abstract
Motivated by the desire for wide-field images with well-defined statistical properties for 21 cm cosmology, we implement an optimal mapping pipeline that computes a maximum likelihood estimator for the sky using the interferometric measurement equation. We demonstrate this “direct optimal mapping” with data from the Hydrogen Epoch of Reionization (HERA) Phase I observations. After validating the pipeline with simulated data, we develop a maximum likelihood figure-of-merit for comparing four sky models at 166 MHz with a bandwidth of 100 kHz. The HERA data agree with the GLEAM catalogs to < 10%. After subtracting the GLEAM point sources, the HERA data discriminate between the different continu..
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Grants
Awarded by Natural Sciences and Engineering Research Council of Canada
Funding Acknowledgements
We thank Bang Nhan for useful discussions. This material is based upon work supported by the National Science Foundation under grant Nos. 1636646 and 1836019 and institutional support from the HERA collaboration partners. This research is funded in part by the Gordon and Betty Moore Foundation through grant GBMF5215 to the Massachusetts Institute of Technology. HERA is hosted by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. K.-F.C. acknowledges the funding support from the Taiwan Think Global Education Trust Fellowship. G.B. acknowledges funding from the INAF PRIN-SKA 2017 project 1.05.01.88.04 (FORECaST), support from the Ministero degli Affari Esteri della Cooperazione Internazionale-Direzione Generale per la Promozione del Sistema Paese Progetto di Grande Rilevanza ZA18GR02, and the National Research Foundation of South Africa (grant No. 113121) as part of the ISARP RADIOSKY2020 Joint Research Scheme, from the Royal Society and the Newton Fund under grant NA150184 and from the National Research Foundation of South Africa (grant No. 103424). P.B. acknowledges funding for part of this research from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 948764), and from STFC Grant ST/T000341/1. E. de L.A. acknowledges the funding support of the UKRI Science and Technology Facilities Council Sky Kilometer Array (SKA) grant. J.S.D. gratefully acknowledges the support of the NSF AAPF award #1701536. N.S.K. acknowledges support from the MIT Pappalardo fellowship. A.L. acknowledges support from the New Frontiers in Research Fund Exploration grant program, the Canadian Institute for Advanced Research (CIFAR) Azrieli Global Scholars program, a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery grant and a Discovery Launch Supplement, the Sloan Research Fellowship, and the William Dawson Scholarship at McGill. We gratefully acknowledge the anonymous referees whose suggestions significantly improved the clarity of this work.