Title:	Improved Constraints on the 21cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
Authors:	Abdurashidova, Zara Adams, Tyrone Aguirre, James E Alexander, Paul Ali, Zaki S Baartman, Rushelle Balfour, Yanga Barkana, Rennan Beardsley, Adam P Bernardi, Gianni Billings, Tashalee S Bowman, Judd D Bradley, Richard F Breitman, Daniela Bull, Philip Burba, Jacob Carey, Steve Carilli, Chris L Cheng, Carina Choudhuri, Samir DeBoer, David R de Lera Acedo, Eloy Dexter, Matt Dillon, Joshua S Ely, John Ewall-Wice, Aaron Fagnoni, Nicolas Fialkov, Anastasia Fritz, Randall Furlanetto, Steven R Gale-Sides, Kingsley Garsden, Hugh Glendenning, Brian Gorce, Adélie Gorthi, Deepthi Greig, Bradley Grobbelaar, Jasper Halday, Ziyaad Hazelton, Bryna J Heimersheim, Stefan Hewitt, Jacqueline N Hickish, Jack Jacobs, Daniel C Julius, Austin Kern, Nicholas S Kerrigan, Joshua Kittiwisit, Piyanat Kohn, Saul A Kolopanis, Matthew Lanman, Adam La Plante, Paul Lewis, David Liu, Adrian Loots, Anita Ma, Yin-Zhe MacMahon, David H E Malan, Lourence Malgas, Keith Malgas, Cresshim Maree, Matthys Marero, Bradley Martinot, Zachary E McBride, Lisa Mesinger, Andrei Mirocha, Jordan Molewa, Mathakane Morales, Miguel F Mosiane, Tshegofalang Muñoz, Julian B Murray, Steven G Nagpal, Vighnesh Neben, Abraham R Nikolic, Bojan Nunhokee, Chuneeta D Nuwegeld, Hans Parsons, Aaron R Pascua, Robert Patra, Nipanjana Pieterse, Samantha Qin, Yuxiang Razavi-Ghods, Nima Robnett, James Rosie, Kathryn Santos, Mario G Sims, Peter Singh, Saurabh Smith, Craig Swarts, Hilton Tan, Jianrong Thyagarajan, Nithyanandan Wilensky, Michael J Williams, Peter K G van Wyngaarden, Pieter Zheng, Haoxuan
Keywords:	Astronomy data analysis (1858) Radio interferometers (1345) Intergalactic medium (813) Reionization (1383) Galaxy formation (595) Cosmology (343)
Issue Date:	14-Mar-2023
Publisher:	American Astronomical Society
Citation:	The Astrophysical Journal,2023, Vol.945,p.43
Abstract:	We report the most sensitive upper limits to date on the 21 cm epoch of reionization power spectrum using 94 nights of observing with Phase I of the Hydrogen Epoch of Reionization Array (HERA). Using similar analysis techniques as in previously reported limits, we find at 95% confidence that Δ2(k = 0.34 h Mpc−1) 457 mK2 at z = 7.9 and that Δ2(k = 0.36 h Mpc−1) 3496 mK2 at z = 10.4, an improvement by a factor of 2.1 and 2.6, respectively. These limits are mostly consistent with thermal noise over a wide range of k after our data quality cuts, despite performing a relatively conservative analysis designed to minimize signal loss. Our results are validated with both statistical tests on the data and end-to-end pipeline simulations. We also report updated constraints on the astrophysics of reionization and the cosmic dawn. Using multiple independent modeling and inference techniques previously employed by HERA Collaboration, we find that the intergalactic medium must have been heated above the adiabatic cooling limit at least as early as z = 10.4, ruling out a broad set of so called “cold reionization” scenarios. If this heating is due to high-mass X-ray binaries during the cosmic dawn, as is generally believed, our result’s 99% credible interval excludes the local relationship between soft X-ray luminosity and star formation and thus requires heating driven by evolved low-metallicity stars.
Description:	Open Access
URI:	http://hdl.handle.net/2289/8208
ISSN:	0004-637X (print) 1538-4357 (online)
Alternative Location:	https://ui.adsabs.harvard.edu/abs/2022arXiv221004912T/abstract https://arxiv.org/abs/2210.04912 https://doi.org/10.3847/1538-4357/acaf50
Copyright:	2023, The Author(s)
Appears in Collections:	Research Papers (A&A)

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.