Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data
Creators: name: Murphy, Geoff G.
name: Bull, Philip
name: Santos, Mario G.
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
name: Bowman, Judd D.
name: Bradley, Richard F.
name: Burba, Jacob
name: Cain, Christopher
name: Carey, Steven
name: Carilli, Chris L.
name: Cheng, Carina
name: DeBoer, David R.
name: Acedo, Eloy de Lera
name: Dexter, Matt
name: Dillon, Joshua S.
name: Eksteen, Nico
name: Ely, John
name: Ewall-Wice, Aaron
name: Fagnoni, Nicolas
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: Hazelton, Bryna J.
name: Hewitt, Jacqueline N.
name: Hickish, Jack
name: Jacobs, Daniel C.
name: Julius, Austin
name: Kariseb, MacCalvin
name: Kern, Nicholas S.
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: 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: Morales, Miguel F.
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: Razavi-Ghods, Nima
name: Robnett, James
name: Rosie, Kathryn
name: Sims, Peter
name: Sipple, Jackson
name: Smith, Craig
name: Swarts, Hilton
name: Thyagarajan, Nithyanandan
name: van Wyngaarden, Pieter
name: Williams, Peter K. G.
name: Zheng, Haoxuan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Observations with radio arrays that target the 21-cm signal originating from the early Universe suffer from a variety of systematic effects. An important class of these are reflections and spurious couplings between antennas. We apply a Hamiltonian Monte Carlo sampler to the modelling and mitigation of these systematics in simulated Hydrogen Epoch of Reionisation Array (HERA) data. This method allows us to form statistical uncertainty estimates for both our models and the recovered visibilities, which is an important ingredient in establishing robust upper limits on the Epoch of Reionisation (EoR) power spectrum. In cases where the noise is large compared to the EoR signal, this approach can constrain the systematics well enough to mitigate them down to the noise level for both systematics studied. Incoherently averaging the recovered power spectra can further reduce the noise and improve recovery. Where the noise level is lower than the EoR, our modelling can mitigate the majority of the reflections and coupling with there being only a minor level of residual systematics. Our approach performs similarly to existing filtering/fitting techniques used in the HERA pipeline, but with the added benefit of rigorously propagating uncertainties. In all cases it does not significantly attenuate the underlying signal.
description: 22 pages, 15 figures, published in MNRAS