B. J. Hazelton
YOU?
Author Swipe
View article: Exploring One-point Statistics in HERA Phase I Data: Effects of Foregrounds and Systematics on Measuring One-point Statistics
Exploring One-point Statistics in HERA Phase I Data: Effects of Foregrounds and Systematics on Measuring One-point Statistics Open
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 effects on measurements made with the Hydrogen Epoch of Re…
View article: Improved Limits on the 21 cm Signal at <i>z</i> = 6.5–7.0 with the Murchison Widefield Array Using Gaussian Information
Improved Limits on the 21 cm Signal at <i>z</i> = 6.5–7.0 with the Murchison Widefield Array Using Gaussian Information Open
We explore the properties of interferometric data from high-redshift 21 cm measurements using the Murchison Widefield Array (MWA). These data contain the redshifted 21 cm signal, contamination from continuum foreground sources, and radiome…
View article: Limits on the 21 cm Power Spectrum at <i>z</i> = 6.5–7.0 from Murchison Widefield Array Observations
Limits on the 21 cm Power Spectrum at <i>z</i> = 6.5–7.0 from Murchison Widefield Array Observations Open
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 analysis uses EoR0-field data, centered at (R.A. = 0 h , decl. …
View article: Investigating mutual coupling in the hydrogen epoch of reionization array and mitigating its effects on the 21-cm power spectrum
Investigating mutual coupling in the hydrogen epoch of reionization array and mitigating its effects on the 21-cm power spectrum Open
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, but some k-modes remain systematics-dominated. Mutual cou…
View article: Limits on the 21 cm power spectrum at z=6.5-7.0 from MWA observations
Limits on the 21 cm power spectrum at z=6.5-7.0 from MWA observations Open
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 analysis uses EoR0-field data, centered at (RA$=0h$, DEC$=-27^{…
View article: pyuvdata v3: an interface for astronomical interferometric data sets in Python
pyuvdata v3: an interface for astronomical interferometric data sets in Python Open
View article: Erratum: “Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array” (2023, ApJ, 957, 78)
Erratum: “Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array” (2023, ApJ, 957, 78) Open
View article: Impacts and Statistical Mitigation of Missing Data on the 21 cm Power Spectrum: A Case Study with the Hydrogen Epoch of Reionization Array
Impacts and Statistical Mitigation of Missing Data on the 21 cm Power Spectrum: A Case Study with the Hydrogen Epoch of Reionization Array Open
The precise characterization and mitigation of systematic effects is one of the biggest roadblocks impeding the detection of the fluctuations of cosmological 21 cm signals. Missing data in radio cosmological experiments, often due to radio…
View article: <tt>matvis</tt>: a matrix-based visibility simulator for fast forward modelling of many-element 21 cm arrays
matvis: a matrix-based visibility simulator for fast forward modelling of many-element 21 cm arrays Open
Detection of the faint 21 cm line emission from the Cosmic Dawn and Epoch of Reionization will require not only exquisite control over instrumental calibration and systematics to achieve the necessary dynamic range of observations but also…
View article: A demonstration of the effect of fringe-rate filtering in the hydrogen epoch of reionization array delay power spectrum pipeline
A demonstration of the effect of fringe-rate filtering in the hydrogen epoch of reionization array delay power spectrum pipeline Open
Radio interferometers targeting the 21cm brightness temperature fluctuations at high redshift are subject to systematic effects that operate over a range of different time-scales. These can be isolated by designing appropriate Fourier filt…
View article: Mitigating calibration errors from mutual coupling with time-domain filtering of 21 cm cosmological radio observations
Mitigating calibration errors from mutual coupling with time-domain filtering of 21 cm cosmological radio observations Open
The 21 cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionization (EoR). This has led to the construction of low-frequency radio interferometric arrays, such as the Hydrogen Epoch of Reioni…
View article: Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data
Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data Open
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 reflections and spurious couplings between antennas. We apply a Ha…
View article: Direct Optimal Mapping Image Power Spectrum and its Window Functions
Direct Optimal Mapping Image Power Spectrum and its Window Functions Open
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 optimal mapping (DOM) to map interferometric visibilities; it…
View article: Mitigating calibration errors from mutual coupling with time-domain filtering of 21 cm cosmological radio observations
Mitigating calibration errors from mutual coupling with time-domain filtering of 21 cm cosmological radio observations Open
The 21 cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation (EoR). This has led to the construction of low-frequency radio interferometric arrays, such as the Hydrogen Epoch of Reioni…
View article: Investigating Mutual Coupling in the Hydrogen Epoch of Reionization Array and Mitigating its Effects on the 21-cm Power Spectrum
Investigating Mutual Coupling in the Hydrogen Epoch of Reionization Array and Mitigating its Effects on the 21-cm Power Spectrum Open
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, but some k-modes remain systematics-dominated. Mutual cou…
View article: pyradiosky: A Python package for Radio SkyModels
pyradiosky: A Python package for Radio SkyModels Open
Pyradiosky is a package to fully and generally describe models of compact, extended and diffuse radio sources with full polarization support.It is designed to support simulations and calibrations of radio interferometry data.It emphasizes …
View article: Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning
Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning Open
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 measurements of the Epoch of Reionization. First results fro…
View article: A demonstration of the effect of fringe-rate filtering in the Hydrogen Epoch of Reionization Array delay power spectrum pipeline
A demonstration of the effect of fringe-rate filtering in the Hydrogen Epoch of Reionization Array delay power spectrum pipeline Open
Radio interferometers targeting the 21cm brightness temperature fluctuations at high redshift are subject to systematic effects that operate over a range of different timescales. These can be isolated by designing appropriate Fourier filte…
View article: Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning
Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning Open
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 measurements of the Epoch of Reionization. First results fro…
View article: matvis: A matrix-based visibility simulator for fast forward modelling of many-element 21 cm arrays
matvis: A matrix-based visibility simulator for fast forward modelling of many-element 21 cm arrays Open
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 achieve the necessary dynamic range of observations but also…
View article: Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data
Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data Open
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 reflections and spurious couplings between antennas. We apply a Ha…
View article: Poster Session II: Cone spacing and S-cone proportion is sufficient to describe varying S-cone regularity across the human central retina
Poster Session II: Cone spacing and S-cone proportion is sufficient to describe varying S-cone regularity across the human central retina Open
The topography of S-cones in the human retina is vital to understand short-wavelength sampling of visual space. In humans S-cones have been reported as randomly arranged within 2° eccentricity and semi-regular more peripherally. A model de…
View article: Direct Optimal Mapping Image Power Spectrum and its Window Functions
Direct Optimal Mapping Image Power Spectrum and its Window Functions Open
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 optimal mapping (DOM) to map interferometric visibilities; it…
View article: Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array
Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array Open
We present deep upper limits from the 2014 Murchison Widefield Array Phase I observing season, with a particular emphasis on identifying the spectral fingerprints of extremely faint radio frequency interference (RFI) contamination in the 2…
View article: Picky with peakpicking: assessing chromatographic peak quality with simple metrics in metabolomics
Picky with peakpicking: assessing chromatographic peak quality with simple metrics in metabolomics Open
View article: Picky with peakpicking: assessing chromatographic peak quality with simple metrics in metabolomics
Picky with peakpicking: assessing chromatographic peak quality with simple metrics in metabolomics Open
Background Chromatographic peakpicking continues to represent a significant bottleneck in automated LC-MS workflows. Uncontrolled false discovery rates and the lack of manually-calibrated quality metrics require researchers to visually eva…
View article: Why and when to expect Gaussian error distributions in epoch of reionization 21-cm power spectrum measurements
Why and when to expect Gaussian error distributions in epoch of reionization 21-cm power spectrum measurements Open
We explore error distributions in Epoch of Reionization 21-cm power spectrum estimators using a combination of mathematical analysis and numerical simulations. We provide closed-form solutions for the error distributions of individual bins…
View article: Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations Open
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 previ…
View article: Search for the Epoch of Reionization with HERA: upper limits on the closure phase delay power spectrum
Search for the Epoch of Reionization with HERA: upper limits on the closure phase delay power spectrum Open
Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionization (EoR) need to achieve an unprecedented dynamic range to separate the weak signal from overwhelming foreground emission…
View article: Characterization of inpaint residuals in interferometric measurements of the epoch of reionization
Characterization of inpaint residuals in interferometric measurements of the epoch of reionization Open
To mitigate the effects of Radio Frequency Interference (RFI) on the data analysis pipelines of 21 cm interferometric instruments, numerous inpaint techniques have been developed. In this paper, we examine the qualitative and quantitative …