Detection of Cosmic Structures using the Bispectrum Phase. II. First Results from Application to Cosmic Reionization Using the Hydrogen Epoch of Reionization Array
Abstract
Characterizing the epoch of reionization (EoR) at via the redshifted 21 cm line of neutral Hydrogen (HI) is critical to modern astrophysics and cosmology, and thus a key science goal of many current and planned low-frequency radio telescopes. The primary challenge to detecting this signal is the overwhelmingly bright foreground emission at these frequencies, placing stringent requirements on the knowledge of the instruments and inaccuracies in analyses. Results from these experiments have largely been limited not by thermal sensitivity but by systematics, particularly caused by the inability to calibrate the instrument to high accuracy. The interferometric bispectrum phase is immune to antenna-based calibration and errors therein, and presents an independent alternative to detect the EoR HI fluctuations while largely avoiding calibration systematics. Here, we provide a demonstration of this technique on a subset of data from the Hydrogen Epoch of Reionization Array (HERA) to place approximate constraints on the brightness temperature of the intergalactic medium (IGM). From this limited data, at we infer "" upper limits on the IGM brightness temperature to be "pseudo" mK at "pseudo" Mpc (data-limited) and "pseudo" mK at "pseudo" Mpc (noise-limited). The "pseudo" units denote only an approximate and not an exact correspondence to the actual distance scales and brightness temperatures. By propagating models in parallel to the data analysis, we confirm that the dynamic range required to separate the cosmic HI signal from the foregrounds is similar to that in standard approaches, and the power spectrum of the bispectrum phase is still data-limited (at dynamic range) indicating scope for further improvement in sensitivity as the array build-out continues.
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Cite
@article{arxiv.2005.10275,
title = {Detection of Cosmic Structures using the Bispectrum Phase. II. First Results from Application to Cosmic Reionization Using the Hydrogen Epoch of Reionization Array},
author = {Nithyanandan Thyagarajan and Chris L. Carilli and Bojan Nikolic and James Kent and Andrei Mesinger and Nicholas S. Kern and Gianni Bernardi and Siyanda Matika and Zara Abdurashidova and James E. Aguirre and Paul Alexander and Zaki S. Ali and Yanga Balfour and Adam P. Beardsley and Tashalee S. Billings and Judd D. Bowman and Richard F. Bradley and Jacob Burba and Steve Carey and Carina Cheng and David R. DeBoer and Matt Dexter and Eloy de Lera Acedo and Joshua S. Dillon and John Ely and Aaron Ewall-Wice and Nicolas Fagnoni and Randall Fritz and Steven R. Furlanetto and Kingsley Gale-Sides and Brian Glendenning and Deepthi Gorthi and Bradley Greig and Jasper Grobbelaar and Ziyaad Halday and Bryna J. Hazelton and Jacqueline N. Hewitt and Jack Hickish and Daniel C. Jacobs and Austin Julius and Joshua Kerrigan and Piyanat Kittiwisit and Saul A. Kohn and Matthew Kolopanis and Adam Lanman and Paul La Plante and Telalo Lekalake and David Lewis and Adrian Liu and David MacMahon and Lourence Malan and Cresshim Malgas and Matthys Maree and Zachary E. Martinot and Eunice Matsetela and Mathakane Molewa and Miguel F. Morales and Tshegofalang Mosiane and Abraham R. Neben and Aaron R. Parsons and Nipanjana Patra and Samantha Pieterse and Jonathan C. Pober and Nima Razavi-Ghods and Jon Ringuette and James Robnett and Kathryn Rosie and Peter Sims and Craig Smith and Angelo Syce and Peter K. G. Williams and Haoxuan Zheng},
journal= {arXiv preprint arXiv:2005.10275},
year = {2020}
}
Comments
22 pages, 12 figures (including sub-figures). Published in PhRvD. Abstract may be slightly abridged compared to the actual manuscript due to length limitations on arXiv