Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
Creators: name: Fagnoni, Nicolas
name: Acedo, Eloy de Lera
name: DeBoer, David R.
name: Abdurashidova, Zara
name: Aguirre, James E.
name: Alexander, Paul
name: Ali, Zaki S.
name: Balfour, Yanga
name: Beardsley, Adam P.
name: Bernardi, Gianni
name: Billings, Tashalee S.
name: Bowman, Judd D.
name: Bradley, Richard F.
name: Bull, Phil
name: Burba, Jacob
name: Carilli, Chris L.
name: Cheng, Carina
name: Dexter, Matt
name: Dillon, Joshua S.
name: Ewall-Wice, Aaron
name: Fritz, Randall
name: Furlanetto, Steve 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: Josaitis, Alec
name: Julius, Austin
name: Kern, Nicholas S.
name: Kerrigan, Joshua
name: Kim, Honggeun
name: Kittiwisit, Piyanat
name: Kohn, Saul A.
name: Kolopanis, Matthew
name: Lanman, Adam
name: La Plante, Paul
name: Lekalake, Telalo
name: Liu, Adrian
name: MacMahon, David
name: Malan, Lourence
name: Malgas, Cresshim
name: Maree, Matthys
name: Martinot, Zachary E.
name: Matsetela, Eunice
name: Parra, Juan Mena
name: Mesinger, Andrei
name: Molewa, Mathakane
name: Morales, Miguel F.
name: Mosiane, Tshegofalang
name: Neben, Abraham R.
name: Nikolic, Bojan
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: Syce, Angelo
name: Thyagarajan, Nithyanandan
name: Williams, Peter K. G.
name: Zheng, Haoxuan
Publisher: name: arXiv
Year: 2019
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The detection of the Epoch of Reionization (EoR) delay power spectrum using a "foreground avoidance method" highly depends on the instrument chromaticity. The systematic effects induced by the radio-telescope spread the foreground signal in the delay domain, which contaminates the EoR window theoretically observable. Applied to the Hydrogen Epoch of Reionization Array (HERA), this paper combines detailed electromagnetic and electrical simulations in order to model the chromatic effects of the instrument, and quantify its frequency and time responses. In particular, the effects of the analogue receiver, transmission cables, and mutual coupling are included. These simulations are able to accurately predict the intensity of the reflections occurring in the 150-m cable which links the antenna to the back-end. They also show that electromagnetic waves can propagate from one dish to another one through large sections of the array due to mutual coupling. The simulated system time response is attenuated by a factor $10^{4}$ after a characteristic delay which depends on the size of the array and on the antenna position. Ultimately, the system response is attenuated by a factor $10^{5}$ after 1400 ns because of the reflections in the cable, which corresponds to characterizable ${k_\parallel}$-modes above 0.7 $h\;\rm{Mpc}^{-1}$ at 150 MHz. Thus, this new study shows that the detection of the EoR signal with HERA Phase I will be more challenging than expected. On the other hand, it improves our understanding of the telescope, which is essential to mitigate the instrument chromaticity.
description: 13 pages, 17 figures - Submitted to MNRAS - 2nd revision