Direct Optimal Mapping for 21cm Cosmology: A Demonstration with the Hydrogen Epoch of Reionization Array
Creators: name: Xu, Zhilei
name: Hewitt, Jacqueline N.
name: Chen, Kai-Feng
name: Kim, Honggeun
name: Dillon, Joshua S.
name: Kern, Nicholas S.
name: Morales, Miguel F.
name: Hazelton, Bryna J.
name: Byrne, Ruby
name: Fagnoni, Nicolas
name: Acedo, Eloy de Lera
name: Abdurashidova, Zara
name: Adams, Tyrone
name: Aguirre, James E.
name: Alexander, Paul
name: Ali, Zaki S.
name: Baartman, Rushelle
name: Balfour, Yanga
name: Beardsley, Adam P.
name: Bernardi, Gianni
name: Billings, Tashalee S.
name: Bowman, Judd D.
name: Bradley, Richard F.
name: Bull, Philip
name: Burba, Jacob
name: Carey, Steven
name: Carilli, Chris L.
name: Cheng, Carina
name: DeBoer, David R.
name: Dexter, Matt
name: Eksteen, Nico
name: Ely, John
name: Ewall-Wice, Aaron
name: Fritz, Randall
name: Furlanetto, Steven R.
name: Gale-Sides, Kingsley
name: Glendenning, Brian
name: Gorthi, Deepthi
name: Greig, Bradley
name: Grobbelaar, Jasper
name: Halday, Ziyaad
name: Hickish, Jack
name: Jacobs, Daniel C.
name: Julius, Austin
name: Kariseb, MacCalvin
name: Kerrigan, Joshua
name: Kittiwisit, Piyanat
name: Kohn, Saul A.
name: Kolopanis, Matthew
name: Lanman, Adam
name: La Plante, Paul
name: Liu, Adrian
name: Loots, Anita
name: Ma, Yin-zhe
name: MacMahon, David Harold Edward
name: Malan, Lourence
name: Malgas, Cresshim
name: Malgas, Keith
name: Marero, Bradley
name: Martinot, Zachary E.
name: Mesinger, Andrei
name: Molewa, Mathakane
name: Mosiane, Tshegofalang
name: Murray, Steven G.
name: Neben, Abraham R.
name: Nikolic, Bojan
name: Nuwegeld, Hans
name: Parsons, Aaron R.
name: Patra, Nipanjana
name: Pieterse, Samantha
name: Pober, Jonathan C.
name: Razavi-Ghods, Nima
name: Robnett, James
name: Rosie, Kathryn
name: Sims, Peter
name: Smith, Craig
name: Swarts, Hilton
name: Thyagarajan, Nithyanandan
name: Van Van Wyngaarden, Pieter
name: Williams, Peter K. G.
name: Zheng, Haoxuan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Motivated by the desire for wide-field images with well-defined statistical properties for 21cm 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 166MHz with a bandwidth of 100kHz. The HERA data agree with the GLEAM catalogs to &lt;10%. After subtracting the GLEAM point sources, the HERA data discriminate between the different continuum sky models, providing most support for the model of Byrne et al. 2021. We report the computation cost for mapping the HERA Phase I data and project the computation for the HERA 320-antenna data; both are feasible with a modern server. The algorithm is broadly applicable to other interferometers and is valid for wide-field and non-coplanar arrays.
description: 16 pages, 10 figures, 2 tables, published on ApJ