200 citations · 1.2k across the 31 of their papers we have counts for
31 papers
Observations of the Cosmic Dawn and Epoch of Reionization with the SKAO: Observational Lessons Learned from Precursors and Pathfinder Instruments
Eloy de Lera Acedo, James Aguirre, Dominic Anstey +34
This chapter summarizes the observational lessons learned after two decades of observations of the Cosmic Dawn (CD) and Epoch of Reionization (EoR) with SKAO pathfinders and precur…
The Murchison Widefield Array Phase III upgrade: Sensitivity Doubled, Number of Baselines Quadrupled, Flexibility Enhanced, and EoR Observations Optimised
S. J. Tingay, M. Johnston-Hollitt, R. B. Wayth +32
We describe the latest iteration of upgrades (designated Phase III) to the Murchison Widefield Array (MWA), in the fourth paper in a series that covers the evolution of the telesco…
Determining Ideal Fields for Epoch of Reionisation Science Using the 21 cm Line
E. Jong, C. Trott, C. D. Nunhokee +1
The upcoming Square Kilometre Array Low Frequency (SKA-Low) interferometer will have the required sensitivity to detect the 21 cm line from neutral hydrogen during the Epoch of Rei…
Improved limits on the 21cm signal at z=6.5-7.0 with the MWA using Gaussian information
Cathryn M. Trott, C. D. Nunhokee, D. Null +29
We explore the properties of interferometric data from high-redshift 21~cm measurements using the Murchison Widefield Array. These data contain redshifted 21~cm signal, contaminati…
Limits on the 21 cm power spectrum at z=6.5-7.0 from MWA observations
C. D. Nunhokee, D. Null, C. M Trott +29
This paper presents the spherically-averaged 21 cm power spectrum derived from Epoch of Reionization (EoR) observations conducted with the Murchison Widefield Array (MWA). The anal…
Square Kilometre Array Science Data Challenge 3a: foreground removal for an EoR experiment
A. Bonaldi, P. Hartley, R. Braun +179
We present and analyse the results of the Science data challenge 3a (SDC3a, https://sdc3.skao.int/challenges/foregrounds), an EoR foreground-removal community-wide exercise organis…
A benchmark analysis of saliency-based explainable deep learning methods for the morphological classification of radio galaxies
M. T. Atemkeng, C. Chuma, S. Zaza +2
This work proposes a saliency-based attribution framework to evaluate and compare 10 state-of-the-art explainability methods for deep learning models in astronomy, focusing on the…
Strategy for mitigation of systematics for EoR experiments with the Murchison Widefield Array
Chuneeta D. Nunhokee, Dev Null, Cathryn M. Trott +4
Observations of the 21 cm signal face significant challenges due to bright astrophysical foregrounds that are several orders of magnitude higher than the brightness of the hydrogen…
A Systematic Review of Low-Rank and Local Low-Rank Matrix Approximation in Big Data Medical Imaging
Sisipho Hamlomo, Marcellin Atemkeng, Yusuf Brima +2
The large volume and complexity of medical imaging datasets are bottlenecks for storage, transmission, and processing. To tackle these challenges, the application of low-rank matri…
A demonstration of the effect of fringe-rate filtering in the Hydrogen Epoch of Reionization Array delay power spectrum pipeline
Hugh Garsden, Philip Bull, Mike Wilensky +94
Radio interferometers targeting the 21cm brightness temperature fluctuations at high redshift are subject to systematic effects that operate over a range of different timescales. T…
Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning
Lindsay M. Berkhout, Daniel C. Jacobs, Zuhra Abdurashidova +93
This paper presents the design and deployment of the Hydrogen Epoch of Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission m…
matvis: A matrix-based visibility simulator for fast forward modelling of many-element 21 cm arrays
Piyanat Kittiwisit, Steven G. Murray, Hugh Garsden +95
Detection of the faint 21 cm line emission from the Cosmic Dawn and Epoch of Reionisation will require not only exquisite control over instrumental calibration and systematics to a…
Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
The HERA Collaboration, Zara Abdurashidova, Tyrone Adams +92
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…
The Correlation Calibration of PAPER-64 data
Tamirat G. Gogo, Yin-Zhe Ma, Piyanat Kittiwisit +21
Observation of redshifted 21-cm signal from the Epoch of Reionization (EoR) is challenging due to contamination from the bright foreground sources that exceed the signal by several…
Automated Detection of Antenna Malfunctions in Large-N Interferometers: A Case Study with the Hydrogen Epoch of Reionization Array
Dara Storer, Joshua S. Dillon, Daniel C. Jacobs +75
We present a framework for identifying and flagging malfunctioning antennas in large radio interferometers. We outline two distinct categories of metrics designed to detect outlier…
First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum
The HERA Collaboration, Zara Abdurashidova, James E. Aguirre +74
We report upper-limits on the Epoch of Reionization (EoR) 21 cm power spectrum at redshifts 7.9 and 10.4 with 18 nights of data ( hours of integration) from Phase I of the…
HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization
The HERA Collaboration, Zara Abdurashidova, James E. Aguirre +81
Recently, the Hydrogen Epoch of Reionization Array (HERA) collaboration has produced the experiment's first upper limits on the power spectrum of 21-cm fluctuations at z~8 and 10.…
Methods of Error Estimation for Delay Power Spectra in Cosmology
Jianrong Tan, Adrian Liu, Nicholas S. Kern +71
Precise measurements of the 21 cm power spectrum are crucial for understanding the physical processes of hydrogen reionization. Currently, this probe is being pursued by low-freque…
Radio multifrequency observations of galaxy clusters. The Abell 399401 pair
C. D. Nunhokee, G. Bernardi, S. Manti +9
Galaxy clusters are assembled via merging of smaller structures, in a process that generates shocks and turbulence in the intra cluster medium and produces radio diffuse emission i…
Measuring HERA's primary beam in-situ: methodology and first results
Chuneeta D. Nunhokee, Aaron R. Parsons, Nicholas S. Kern +64
The central challenge in 21~cm cosmology is isolating the cosmological signal from bright foregrounds. Many separation techniques rely on the accurate knowledge of the sky and the…
Foreground modelling via Gaussian process regression: an application to HERA data
Abhik Ghosh, Florent Mertens, Gianni Bernardi +70
The key challenge in the observation of the redshifted 21-cm signal from cosmic reionization is its separation from the much brighter foreground emission. Such separation relies on…
DAYENU: A Simple Filter of Smooth Foregrounds for Intensity Mapping Power Spectra
Aaron Ewall-Wice, Nicholas Kern, Joshua S. Dillon +14
We introduce DAYENU, a linear, spectral filter for HI intensity mapping that achieves the desirable foreground mitigation and error minimization properties of inverse co-variance w…
Redundant-Baseline Calibration of the Hydrogen Epoch of Reionization Array
Joshua S. Dillon, Max Lee, Zaki S. Ali +76
In 21 cm cosmology, precision calibration is key to the separation of the neutral hydrogen signal from very bright but spectrally-smooth astrophysical foregrounds. The Hydrogen Epo…
Absolute Calibration Strategies for the Hydrogen Epoch of Reionization Array and Their Impact on the 21 cm Power Spectrum
Nicholas S. Kern, Joshua S. Dillon, Aaron R. Parsons +69
We discuss absolute calibration strategies for Phase I of the Hydrogen Epoch of Reionization Array (HERA), which aims to measure the cosmological 21 cm signal from the Epoch of Rei…