122 citations · 559 across the 24 of their papers we have counts for
25 papers
The burgeoning rise of the 21-cm forest I: constraints on the optical depth of the intergalactic medium at
Chanasorn Kongprachaya, Gianni Bernardi, Emilio Ceccotti +3
The redshifted 21-cm line is a promising probe of the Epoch of Reionization, during which the first generation of stars ionized the InterGalactic Medium (IGM). We aimed to constrai…
Scalable Bayesian data curation for next-generation radio experiments
S. A. K. Leeney, E. de Lera Acedo, W. J. Handley +42
Next-generation radio telescopes produce data volumes that preclude manual quality assessment, yet data curation remains essential for science. We present a general, fully automati…
Optimisation of calibration sources for global 21-cm experiments: the REACH case
Adarsh Kumar Dash, Dominic Anstey, Harry T. J. Bevins +41
The spin-flip 21-cm signal from the Cosmic Dawn and the Epoch of Reionization is an essential probe of the conditions that led to the formation of the first luminous objects in the…
Circuit Modeling for In Situ 21 cm Radiometer Calibration
Gary Vincent Charles Allen, Saurabh Pegwal, Dirk de Villiers +42
Recent experiments in cosmology, particularly those aimed at detecting the faint, redshifted, global 21 cm hydrogen line (depth < ~200 mK, z > 7.5), have imposed stringent new requ…
First Results from HERA Phase II
The HERA Collaboration, Zuhra Abdurashidova, Tyrone Adams +83
We report the first upper limits on the power spectrum of 21-cm fluctuations during the Epoch of Reionization and Cosmic Dawn from Phase II of the Hydrogen Epoch of Reionization Ar…
Exploring One-point Statistics in HERA Phase I Data: Effects of Foregrounds and Systematics on Measuring One-Point Statistics
Honggeun Kim, Jacqueline N. Hewitt, Nicholas S. Kern +61
Measuring one-point statistics in redshifted 21 cm intensity maps offers an opportunity to explore non-Gaussian features of the early universe. We assess the impact of instrumental…
Intrinsic Cross Polarization Ratio maps from all-sky observations with the SKA-Low prototype station Aperture Array Verification System 2
Giulia Macario, Giuseppe Pupillo, Gianni Bernardi +10
The low-frequency radio telescope of the Square Kilometre Array (SKA-Low), currently under construction in the remote Murchison shire in the Western Australia's outback, will obser…
Impacts and Statistical Mitigation of Missing Data on the 21cm Power Spectrum: A Case Study with the Hydrogen Epoch of Reionization Array
Kai-Feng Chen, Michael J. Wilensky, Adrian Liu +66
The precise characterization and mitigation of systematic effects is one of the biggest roadblocks impeding the detection of the fluctuations of cosmological 21cm signals. Missing…
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…
Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data
Geoff G. Murphy, Philip Bull, Mario G. Santos +76
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 reflect…
Direct Optimal Mapping Image Power Spectrum and its Window Functions
Zhilei Xu, Honggeun Kim, Jacqueline N. Hewitt +79
The key to detecting neutral hydrogen during the epoch of reionization (EoR) is to separate the cosmological signal from the dominating foreground radiation. We developed direct op…
Validation of the HERA Phase I Epoch of Reionization 21 cm Power Spectrum Software Pipeline
James E. Aguirre, Steven G. Murray, Robert Pascua +73
We describe the validation of the HERA Phase I software pipeline by a series of modular tests, building up to an end-to-end simulation. The philosophy of this approach is to valida…
A 21-cm power spectrum at 48 MHz, using the Owens Valley Long Wavelength Array
Hugh Garsden, Lincoln Greenhill, Gianni Bernardi +6
The Large-aperture Experiment to detect the Dark Age (LEDA) was designed to measure the 21-cm signal from neutral hydrogen at Cosmic Dawn, 15-30. Using observations mad…
Spectral index of the Galactic foreground emission in the 50-87 MHz range
Marta Spinelli, Gianni Bernardi, Hugh Garsden +4
Total-power radiometry with individual meter-wave antennas is a potentially effective way to study the Cosmic Dawn () through measurement of sky brightness arising from th…
Imaging and Modeling Data from the Hydrogen Epoch of Reionization Array
C. L. Carilli{1, 2}, N. Thyagarajan{1} +43
We analyze data from the Hydrogen Epoch of Reionization Array. This is the third in a series of papers on the closure phase delay-spectrum technique designed to detect the HI 21cm…
Simulations of Galactic polarized synchrotron emission for Epoch of Reionization observations
M. Spinelli, G. Bernardi, M. G. Santos
The detection of the redshifted cosmological ~cm line signal requires the removal of the Galactic and extragalactic foreground emission, which is orders of magnitude brighter a…
Bayesian constraints on the global 21-cm signal from the Cosmic Dawn
G. Bernardi, J. T. L. Zwart, D. Price +7
The birth of the first luminous sources and the ensuing epoch of reionization are best studied via the redshifted 21-cm emission line, the signature of the first two imprinting the…
Empirical Covariance Modeling for 21 cm Power Spectrum Estimation: A Method Demonstration and New Limits from Early Murchison Widefield Array 128-Tile Data
Joshua S. Dillon, Abraham R. Neben, Jacqueline N. Hewitt +52
The separation of the faint cosmological background signal from bright astrophysical foregrounds remains one of the most daunting challenges of mapping the high-redshift intergalac…
Measuring Phased-Array Antenna Beampatterns with High Dynamic Range for the Murchison Widefield Array using 137 MHz ORBCOMM Satellites
A. R. Neben, R. F. Bradley, J. N. Hewitt +26
Detection of the fluctuations in 21 cm line emission from neutral hydrogen during the Epoch of Reionization in thousand hour integrations poses stringent requirements on calibratio…
Digital Signal Processing using Stream High Performance Computing: A 512-input Broadband Correlator for Radio Astronomy
J. Kocz, L. J Greenhill, B. R. Barsdell +16
A "large-N" correlator that makes use of Field Programmable Gate Arrays and Graphics Processing Units has been deployed as the digital signal processing system for the Long Wavelen…
A Scalable Hybrid FPGA/GPU FX Correlator
J. Kocz, L. J. Greenhill, B. R. Barsdell +8
Radio astronomical imaging arrays comprising large numbers of antennas, O(10^2-10^3) have posed a signal processing challenge because of the required O(N^2) cross correlation of si…
HI Epoch of Reionization Arrays
L. J. Greenhill, G. Bernardi
There are few data available with which to constrain the thermal history of the intergalactic medium (IGM) following global recombination. Thus far, most constraints flow from anal…