Publications (35)
The Murchison Widefield Array 21 cm Power Spectrum Analysis Methodology
Daniel C. Jacobs, B. J. Hazelton, C. M. Trott +61
We present the 21 cm power spectrum analysis approach of the Murchison Widefield Array Epoch of Reionization project. In this paper, we compare the outputs of multiple pipelines fo…
The low-frequency environment of the Murchison Widefield Array: radio-frequency interference analysis and mitigation
A. R. Offringa, R. B. Wayth, N. Hurley-Walker +62
The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope built in Western Australia at one of the locations of the future Square Kilometre Array (…
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…
Aliasing from Galactic Plane Setting in Widefield Radio Interferometry
N. Barry, J. L. B. Line, C. R. Lynch +2
Measurements with widefield radio interferometers often include the near-infinite gradient between the sky and the horizon. This causes aliasing inherent to the measurement itself,…
Calibration Requirements for Detecting the 21 cm Epoch of Reionization Power Spectrum and Implications for the SKA
N. Barry, B. Hazelton, I. Sullivan +2
21 cm Epoch of Reionization observations promise to transform our understanding of galaxy formation, but these observations are impossible without unprecedented levels of instrumen…
Foregrounds in Wide-Field Redshifted 21 cm Power Spectra
Nithyanandan Thyagarajan, Daniel C. Jacobs, Judd D. Bowman +61
Detection of 21~cm emission of HI from the epoch of reionization, at redshifts z>6, is limited primarily by foreground emission. We investigate the signatures of wide-field measure…
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…
Epoch of Reionization Power Spectrum Limits from Murchison Widefield Array Data Targeted at EoR1 Field
M. Rahimi, B. Pindor, J. L. B. Line +28
Current attempts to measure the 21cm Power Spectrum of neutral hydrogen during the Epoch of Reionization are limited by systematics which produce measured upper limits above both t…
First Season MWA EoR Power Spectrum Results at Redshift 7
A. P. Beardsley, B. J. Hazelton, I. S. Sullivan +63
The Murchison Widefield Array (MWA) has collected hundreds of hours of Epoch of Reionization (EoR) data and now faces the challenge of overcoming foreground and systematic contamin…
The Necessity of Individually Validated Beam Models for an Interferometric Epoch of Reionization Detection
A. Chokshi, N. Barry, J. L. B. Line +3
A first statistical detection of the 21-cm Epoch of Reionization (EoR) is on the horizon, as cosmological volumes of the Universe become accessible via the adoption of low-frequenc…
Deep multi-redshift limits on Epoch of Reionisation 21cm Power Spectra from Four Seasons of Murchison Widefield Array Observations
Cathryn M. Trott, C. H. Jordan, S. Midgley +33
We compute the spherically-averaged power spectrum from four seasons of data obtained for the Epoch of Reionisation (EoR) project observed with the Murchison Widefield Array (MWA).…
The challenges of low-frequency radio polarimetry: lessons from the Murchison Widefield Array
Emil Lenc, C. S. Anderson, N. Barry +26
We present techniques developed to calibrate and correct Murchison Widefield Array (MWA) low frequency (72-300 MHz) radio observations for polarimetry. The extremely wide field-of-…
Dual Polarization Measurements of MWA Beampatterns at 137 MHz
A. Chokshi, J. L. B. Line, N. Barry +5
The wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionised radio astronomy. Despite their cons…
Parametrising Epoch of Reionization foregrounds: A deep survey of low-frequency point-source spectra with the MWA
A. R. Offringa, C. M. Trott, N. Hurley-Walker +38
Experiments that pursue detection of signals from the Epoch of Reionization (EoR) are relying on spectral smoothness of source spectra at low frequencies. This article empirically…
Verifying the Australian MWA EoR pipeline II: fundamental limits of the AusEoRPipe and the impact of instrumental effects
J. L. B. Line, C. M. Trott, N. Barry +2
Detection of the weak cosmological signal from high-redshift hydrogen demands careful data analysis and an understanding of the full instrument signal chain. Here we use the WODEN…
Delay Spectrum with Phase-Tracking Arrays: Extracting the HI power spectrum from the Epoch of Reionization
Sourabh Paul, Shiv K. Sethi, Miguel F. Morales +51
The Detection of redshifted 21 cm emission from the epoch of reionization (EoR) is a challenging task owing to strong foregrounds that dominate the signal. In this paper, we propos…
Low frequency observations of linearly polarized structures in the interstellar medium near the south Galactic pole
Emil Lenc, B. M. Gaensler, X. H. Sun +76
We present deep polarimetric observations at 154 MHz with the Murchison Widefield Array (MWA), covering 625 deg^2 centered on RA=0 h, Dec=-27 deg. The sensitivity available in our…
Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array
Cathryn M. Trott, Catherine A. Watkinson, Christopher H. Jordan +42
We apply two methods to estimate the 21~cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired wit…
Constraining the 21cm brightness temperature of the IGM at =6.6 around LAEs with the Murchison Widefield Array
Cathryn M. Trott, C. H. Jordan, J. L. B. Line +29
The locations of Ly- emitting galaxies (LAEs) at the end of the Epoch of Reionisation (EoR) are expected to correlate with regions of ionised hydrogen, traced by the redshifted…
Improving the Epoch of Reionization Power Spectrum Results from Murchison Widefield Array Season 1 Observations
N. Barry, M. Wilensky, C. M. Trott +27
Measurements of 21 cm Epoch of Reionization (EoR) structure are subject to systematics originating from both the analysis and the observation conditions. Using 2013 data from the M…
Robust statistics toward detection of the 21 cm signal from the Epoch of Reionisation
Cathryn M. Trott, Shih Ching Fu, Steven Murray +26
We explore methods for robust estimation of the 21 cm signal from the Epoch of Reionisation (EoR). A Kernel Density Estimator (KDE) is introduced for measuring the spatial temperat…
A High Reliability Survey of Discrete Epoch of Reionization Foreground Sources in the MWA EoR0 Field
P. A. Carroll, J. Line, M. F. Morales +61
Detection of the Epoch of Reionization HI signal requires a precise understanding of the intervening galaxies and AGN, both for instrumental calibration and foreground removal. We…
NEST: A Comprehensive Model for Scintillation Yield in Liquid Xenon
M. Szydagis, N. Barry, K. Kazkaz +7
A comprehensive model for explaining scintillation yield in liquid xenon is introduced. We unify various definitions of work function which abound in the literature and incorporate…
First Season MWA Phase II EoR Power Spectrum Results at Redshift 7
W. Li, J. C. Pober, N. Barry +44
The compact configuration of Phase II of the Murchison Widefield Array (MWA) consists of both a redundant subarray and pseudo-random baselines, offering unique opportunities to per…
The FHD/ppsilon Epoch of Reionization Power Spectrum Pipeline
N. Barry, A. P. Beardsley, R. Byrne +4
Epoch of Reionization data analysis requires unprecedented levels of accuracy in radio interferometer pipelines. We have developed an imaging power spectrum analysis to meet these…
Comparing Redundant and Sky Model Based Interferometric Calibration: A First Look with Phase II of the MWA
W. Li, J. C. Pober, B. J. Hazelton +53
Interferometric arrays seeking to measure the 21 cm signal from the Epoch of Reionization must contend with overwhelmingly bright emission from foreground sources. Accurate recover…
Confirmation of Wide-Field Signatures in Redshifted 21 cm Power Spectra
Nithyanandan Thyagarajan, Daniel C. Jacobs, Judd D. Bowman +52
We confirm our recent prediction of the "pitchfork" foreground signature in power spectra of high-redshift 21 cm measurements where the interferometer is sensitive to large-scale s…
Spectral energy distribution and radio halo of NGC 253 at low radio frequencies
A. D. Kapinska, L. Staveley-Smith, R. Crocker +67
We present new radio continuum observations of NGC253 from the Murchison Widefield Array at frequencies between 76 and 227 MHz. We model the broadband radio spectral energy distrib…
A Laboratory-based Hard X-ray Monochromator for High-Resolution X-ray Emission Spectroscopy and X-ray Absorption Near Edge Structure Measurements
G. T. Seidler, D. R. Mortensen, A. J. Remesnik +5
We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low poer x-ray (bremsstrahlung) tube source, a spherically-bent crystal analyzer (S…
A new MWA limit on the 21 cm Power Spectrum at Redshifts 13 17
S. Yoshiura, B. Pindor, J. L. B. Line +29
Observations in the lowest MWA band between MHz have the potential to constrain the distribution of neutral hydrogen in the intergalactic medium at redshift .…
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…
First Limits on the 21 cm Power Spectrum during the Epoch of X-ray heating
A. Ewall-Wice, Joshua S. Dillon, J. N. Hewitt +62
We present first results from radio observations with the Murchison Widefield Array seeking to constrain the power spectrum of 21 cm brightness temperature fluctuations between the…
CHIPS: The Cosmological HI Power Spectrum Estimator
Cathryn M. Trott, Bart Pindor, Pietro Procopio +49
Detection of the cosmological neutral hydrogen signal from the Epoch of Reionization, and estimation of its basic physical parameters, is the principal scientific aim of many curre…
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…
Verifying the Australian MWA EoR pipeline I: 21-cm sky model and correlated measurement density
J. L. B. Line, C. M. Trott, J. H. Cook +3
We present the first of two papers dedicated to verifying the Australian Epoch of Reionisation pipeline (AusEoRPipe) through simulation. The AusEoRPipe aims to disentangle 21-cm ra…