657 citations · 2.1k across the 51 of their papers we have counts for
52 papers
Properties and limitations of linear models for mutual coupling in 21 cm arrays
Vincent MacKay, Robert Pascua, Eleanor Rath +7
Mutual coupling between elements of low-frequency arrays is a leading systematic for 21 cm cosmology, leaking bright foregrounds into otherwise clean regions of the power spectrum.…
A Fast Direct Solver for Mutual Coupling Analysis of Large Arrays of Reflector Antennas
Quentin Gueuning, Eloy de Lera Acedo, Anthony Keith Brown +1
Mutual coupling is a dominant systematic effect in dense reflector arrays, imprinting direction-dependent and frequency-dependent structure on embedded element patterns (EEPs) and…
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…
High Dimensional Beam Inference II: Inference of a Perturbed HERA Beam from Simulated Visibility Data
Michael J. Wilensky, Philip Bull, Nicolas Fagnoni
Accurate beam modeling is important in many radio astronomy applications. In this paper, we focus on beam modeling for 21-cm intensity mapping experiments using radio interferomete…
A Generalized Method for Characterizing 21-cm Power Spectrum Signal Loss from Temporal Filtering of Drift-scanning Visibilities
Robert Pascua, Zachary E. Martinot, Adrian Liu +7
A successful detection of the cosmological 21-cm signal from intensity mapping experiments (for example, during the Epoch of Reioinization or Cosmic Dawn) is contingent on the supp…
Investigating Mutual Coupling in the Hydrogen Epoch of Reionization Array and Mitigating its Effects on the 21-cm Power Spectrum
E. Rath, R. Pascua, A. T. Josaitis +78
Interferometric experiments designed to detect the highly redshifted 21-cm signal from neutral hydrogen are producing increasingly stringent constraints on the 21-cm power spectrum…
High-dimensional inference of radio interferometer beam patterns I: Parametric model of the HERA beams
Michael J. Wilensky, Jacob Burba, Philip Bull +6
Accurate modelling of the primary beam is an important but difficult task in radio astronomy. For high dynamic range problems such as 21cm intensity mapping, small modelling errors…
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…
The Impact of Beam Variations on Power Spectrum Estimation for 21 cm Cosmology II: Mitigation of Foreground Systematics for HERA
Honggeun Kim, Nicholas S. Kern, Jacqueline N. Hewitt +7
One key challenge in detecting 21 cm cosmological signal at z > 6 is to separate the cosmological signal from foreground emission. This can be studied in a power spectrum space whe…
Search for the Epoch of Reionisation with HERA: Upper Limits on the Closure Phase Delay Power Spectrum
Pascal M. Keller, Bojan Nikolic, Nithyanandan Thyagarajan +80
Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionisation (EoR) need to achieve an unprecedented dynamic range to sep…
On the use of temporal filtering for mitigating galactic synchrotron calibration bias in 21 cm reionization observations
Ntsikelelo Charles, Nicholas Kern, Gianni Bernardi +4
Precision antenna calibration is required for mitigating the impact of foreground contamination in 21 cm cosmological radio surveys. One widely studied source of error is the effec…
Bayesian jackknife tests with a small number of subsets: Application to HERA 21cm power spectrum upper limits
Michael J. Wilensky, Fraser Kennedy, Philip Bull +2
We present a Bayesian jackknife test for assessing the probability that a data set contains biased subsets, and, if so, which of the subsets are likely to be biased. The test can b…
The Impact of Beam Variations on Power Spectrum Estimation for 21-cm Cosmology I: Simulations of Foreground Contamination for HERA
Honggeun Kim, Bang D. Nhan, Jacqueline N. Hewitt +7
Detecting cosmological signals from the Epoch of Reionization (EoR) requires high-precision calibration to isolate the cosmological signals from foreground emission. In radio inter…
Characterization Of Inpaint Residuals In Interferometric Measurements of the Epoch Of Reionization
Michael Pagano, Jing Liu, Adrian Liu +75
Radio Frequency Interference (RFI) is one of the systematic challenges preventing 21cm interferometric instruments from detecting the Epoch of Reionization. To mitigate the effects…
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…
Impact of instrument and data characteristics in the interferometric reconstruction of the 21 cm power spectrum
Adélie Gorce, Samskruthi Ganjam, Adrian Liu +75
Combining the visibilities measured by an interferometer to form a cosmological power spectrum is a complicated process. In a delay-based analysis, the mapping between instrumental…
Direct Optimal Mapping for 21cm Cosmology: A Demonstration with the Hydrogen Epoch of Reionization Array
Zhilei Xu, Jacqueline N. Hewitt, Kai-Feng Chen +78
Motivated by the desire for wide-field images with well-defined statistical properties for 21cm cosmology, we implement an optimal mapping pipeline that computes a maximum likeliho…
Simulations of primary beam effects on the cosmic bispectrum phase observed with the Hydrogen Epoch of Reionization Array
N. Charles, G. Bernardi, H. L. Bester +9
The 21~cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation. The main difficulty in measuring the 21 cm signal is the presen…
Array Element Coupling in Radio Interferometry I: A Semi-Analytic Approach
Alec T. Josaitis, Aaron Ewall-Wice, Nicolas Fagnoni +1
We derive a general formalism for interferometric visibilities, which considers first-order antenna-antenna coupling and assumes steady-state, incident radiation. We simulate such…