Publications (53)
Modelling of the Spectral Energy Distribution of Fornax A: Leptonic and Hadronic Production of High Energy Emission from the Radio Lobes
B. McKinley, R. Yang, M. López-Caniego +52
We present new low-frequency observations of the nearby radio galaxy Fornax A at 154 MHz with the Murchison Widefield Array, microwave flux-density measurements obtained from WMAP…
Extragalactic Peaked-Spectrum Radio Sources at Low Frequencies
J. R. Callingham, R. D. Ekers, B. M. Gaensler +21
We present a sample of 1,483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM)…
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…
An analysis of the halo and relic radio emission from Abell 3376 from Murchison Widefield Array observations
Lijo T. George, K. S. Dwarakanath, M. Johnston-Hollitt +48
We have carried out multiwavelength observations of the near-by () rich, merging galaxy cluster Abell 3376 with the Murchison Widefield Array (MWA). As a part of the GaLac…
Characterisation of the ionosphere above the Murchison Radio Observatory using the Murchison Widefield Array
C. H. Jordan, S. Murray, C. M. Trott +6
We detail new techniques for analysing ionospheric activity, using Epoch of Reionisation (EoR) datasets obtained with the Murchison Widefield Array (MWA), calibrated by the `Real-T…
A study of halo and relic radio emission in merging clusters using the Murchison Widefield Array
L. T. George, K. S. Dwarakanath, M. Johnston-Hollitt +18
We have studied radio haloes and relics in nine merging galaxy clusters using the Murchison Widefield Array (MWA). The images used for this study were obtained from the GaLactic an…
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…
Low Radio Frequency Observations and Spectral Modelling of the Remnant of Supernova 1987A
J. R. Callingham, B. M. Gaensler, G. Zanardo +17
We present Murchison Widefield Array observations of the supernova remnant (SNR) 1987A between 72 and 230 MHz, representing the lowest frequency observations of the source to date.…
GLEAM: The GaLactic and Extragalactic All-sky MWA survey
R. B. Wayth, E. Lenc, M. E. Bell +52
GLEAM, the GaLactic and Extragalactic All-sky MWA survey, is a survey of the entire radio sky south of declination +25 deg at frequencies between 72 and 231 MHz, made with the Murc…
A search for long-timescale, low-frequency radio transients
Tara Murphy, David L. Kaplan, Steve Croft +30
We present a search for transient and highly variable sources at low radio frequencies (150-200 MHz) that explores long timescales of 1-3 years. We conducted this search by compari…
Simultaneous Planck, Swift, and Fermi observations of X-ray and gamma-ray selected blazars
P. Giommi, G. Polenta, A. Lahteenmaki +92
We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard X-ray, and gamma-ray bands.…
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…
Planck intermediate results. XVIII The millimetre and sub-millimetre emission from planetary nebulae
Planck Collaboration, M. Arnaud, F. Atrio-Barandela +158
Late stages of stellar evolution are characterized by copious mass-loss events whose signature is the formation of circumstellar envelopes (CSE). Planck multi-frequency measurement…
Galactic synchrotron emissivity measurements between 250° < l < 355° from the GLEAM survey with the MWA
H. Su, N. Hurley-Walker, C. A. Jackson +20
Synchrotron emission pervades the Galactic plane at low radio frequencies, originating from cosmic ray electrons interacting with the Galactic magnetic field. Using a low-frequency…
The Importance of Wide-field Foreground Removal for 21 cm Cosmology: A Demonstration With Early MWA Epoch of Reionization Observations
J. C. Pober, B. J. Hazelton, A. P. Beardsley +66
In this paper we present observations, simulations, and analysis demonstrating the direct connection between the location of foreground emission on the sky and its location in cosm…
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 Simultaneous Medicina-Planck Experiment (SiMPlE): data acquisition, reduction and first results
P. Procopio, M. Massardi, S. Righini +13
The Simultaneous Medicina-{\it Planck} Experiment (SiMPlE) is aimed at observing a selected sample of 263 extragalactic and Galactic sources with the Medicina 32-m single dish radi…
A 20 GHz Bright Sample for Delta > 72 deg - II. Multi-frequency Follow-up
R. Ricci, S. Righini, R. Verma +10
We present follow-up observations at 5, 8 and 30 GHz of the K-band Northern Wide Survey (KNoWS) 20 GHz Bright Sample, performed with the 32-m Medicina Radio Telescope and the 32-m…
First Look Murchison Widefield Array observations of Abell 3667
L. Hindson, M. Johnston-Hollitt, N. Hurley-Walker +51
The Murchison Widefield Array (MWA) is a new low frequency interferometric radio telescope, operating in the remote Murchison Radio Observatory in Western Australia. In this paper…
A 20 GHz bright sample for δ > +72°: I. Catalogue
S. Righini, E. Carretti, R. Ricci +9
During 2010-2011, the Medicina 32-m dish hosted the 7-feed 18-26.5 GHz receiver built for the Sardinia Radio Telescope, with the goal to perform its commissioning. This opportunity…
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 (…
Galactic synchrotron distribution derived from 152 HII region absorption features in the full GLEAM survey
H. Su, J. P. Macquart, N. Hurley-Walker +22
We derive the synchrotron distribution in the Milky Way disk from HII region absorption observations over -40° < l < 40° at six frequencies of 76.2, 83.8, 91.5, 99.2, 106.9, and…
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…
Planck early results. XX. New light on anomalous microwave emission from spinning dust grains
Planck Collaboration, P. A. R. Ade, N. Aghanim +213
Anomalous microwave emission (AME) has been observed by numerous experiments in the frequency range ~10-60 GHz. Using Planck maps and multi-frequency ancillary data, we have constr…
Mining the Herschel-ATLAS: submillimeter-selected blazars in equatorial fields
M. López-Caniego, J. González-Nuevo, M. Massardi +29
The Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) provides an unprecedented opportunity to search for blazars at sub-mm wavelengths. We cross-matched the FIRST radio…
A high resolution foreground model for the MWA EoR1 field: model and implications for EoR power spectrum analysis
P. Procopio, R. B. Wayth, J. Line +23
The current generation of experiments aiming to detect the neutral hydrogen signal from the Epoch of Reionisation (EoR) is likely to be limited by systematic effects associated wit…
Low frequency spectral energy distributions of radio pulsars detected with the Murchison Widefield Array
Tara Murphy, David L. Kaplan, Martin E. Bell +24
We present low-frequency spectral energy distributions of 60 known radio pulsars observed with the Murchison Widefield Array (MWA) telescope. We searched the GaLactic and Extragala…
Ionospheric Modelling using GPS to Calibrate the MWA. II: Regional ionospheric modelling using GPS and GLONASS to estimate ionospheric gradients
B. S. Arora, J. Morgan, S. M. Ord +18
We estimate spatial gradients in the ionosphere using the Global Positioning System (GPS) and GLONASS (Russian global navigation system) observations, utilising data from multiple…
Planck early results. III. First assessment of the Low Frequency Instrument in-flight performance
A. Mennella, M. Bersanelli, R. C. Butler +158
The scientific performance of the Planck Low Frequency Instrument (LFI) after one year of in-orbit operation is presented. We describe the main optical parameters and discuss photo…
The jet/wind outflow in Centaurus A: a local laboratory for AGN feedback
B. McKinley, S. J. Tingay, E. Carretti +20
We present new radio and optical images of the nearest radio galaxy Centaurus A and its host galaxy NGC 5128. We focus our investigation on the northern transition region, where en…
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…
WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
A. R. Offringa, B. McKinley, N. Hurley-Walker +50
Astronomical widefield imaging of interferometric radio data is computationally expensive, especially for the large data volumes created by modern non-coplanar many-element arrays.…
Broadband Spectral Modeling of the Extreme Gigahertz-Peaked Spectrum Radio Source PKS B0008-421
J. R. Callingham, B. M. Gaensler, R. D. Ekers +40
We present broadband observations and spectral modeling of PKS B0008-421, and identify it as an extreme gigahertz-peaked spectrum (GPS) source. PKS B0008-421 is characterized by th…
High-energy sources at low radio frequency: the Murchison Widefield Array view of Fermi blazars
M. Giroletti, F. Massaro, R. D'Abrusco +54
Low-frequency radio arrays are opening a new window for the study of the sky, both to study new phenomena and to better characterize known source classes. Being flat-spectrum sourc…
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…
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…
Calibration and Stokes Imaging with Full Embedded Element Primary Beam Model for the Murchison Widefield Array
M. Sokolowski, T. Colegate, A. T. Sutinjo +22
The Murchison Widefield Array (MWA), located in Western Australia, is one of the low-frequency precursors of the international Square Kilometre Array (SKA) project. In addition to…
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…
The Murchison Widefield Array Correlator
S. M. Ord, B. Crosse, D. Emrich +64
The Murchison Widefield Array (MWA) is a Square Kilometre Array (SKA) Precursor. The telescope is located at the Murchison Radio--astronomy Observatory (MRO) in Western Australia (…
On the detection and tracking of space debris using the Murchison Widefield Array. I. Simulations and test observations demonstrate feasibility
S. J. Tingay, D. L. Kaplan, B. McKinley +60
The Murchison Widefield Array (MWA) is a new low frequency interferomeric radio telescope. The MWA is the low frequency precursor to the Square Kilometre Array (SKA) and is the fir…
The radio spectral energy distribution of infrared-faint radio sources
A. Herzog, R. P. Norris, E. Middelberg +57
Infrared-faint radio sources (IFRS) are a class of radio-loud (RL) active galactic nuclei (AGN) at high redshifts (z > 1.7) that are characterised by their relative infrared faintn…
Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources
Planck Collaboration, J. Aatrokoski, P. A. R. Ade +246
Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact S…
A Large Scale, Low Frequency Murchison Widefield Array Survey of Galactic HII regions between 260< l <\340
L. Hindson, M. Johnston-Hollitt, N. Hurley-Walker +40
We have compiled a catalogue of HII regions detected with the Murchison Widefield Array (MWA) between 72 and 231MHz. The multiple frequency bands provided by the MWA allow us ident…
Planck early results XIV: ERCSC validation and extreme radio sources
Planck Collaboration, P. A. R. Ade, N. Aghanim +206
Planck's all sky surveys at 30-857 GHz provide an unprecedented opportunity to follow the radio spectra of a large sample of extragalactic sources to frequencies 2-20 times higher…
Limits of noise and confusion in the MWA GLEAM year 1 survey
T. M. O. Franzen, C. A. Jackson, J. R. Callingham +21
The GaLactic and Extragalactic All-sky MWA survey (GLEAM) is a new relatively low resolution, contiguous 72-231 MHz survey of the entire sky south of declination +25 deg. In this p…
Planck Early Results. V. The Low Frequency Instrument data processing
A. Zacchei, D. Maino, C. Baccigalupi +146
We describe the processing of data from the Low Frequency Instrument (LFI) used in production of the Planck Early Release Compact Source Catalogue (ERCSC). In particular, we discus…
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…
Murchison Widefield Array and XMM-Newton observations of the Galactic supernova remnant G5.9+3.1
D. OniÄ, M. D. FilipoviÄ, I. BojiÄiÄ +27
In this paper we discuss the radio continuum and X-ray properties of the so-far poorly studied Galactic supernova remnant (SNR) G5.9+3.1. We present the radio spectral energy distr…
The first Murchison Widefield Array low frequency radio observations of cluster scale non-thermal emission: the case of Abell 3667
L. Hindson, M. Johnston-Hollitt, N. Hurley-Walker +51
We present the first Murchison Widefield Array observations of the well-known cluster of galaxies Abell 3667 (A3667) between 105 and 241 MHz. A3667 is one of the best known example…
The GLEAM 200 MHz Local Radio Luminosity Function for AGN and Star-forming Galaxies
T. M. O. Franzen, N. Seymour, E. M. Sadler +24
The GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) is a radio continuum survey at 76-227 MHz of the entire southern sky (Declination ) with an angular…
Ionospheric modelling using GPS to calibrate the MWA. 1: Comparison of first order ionospheric effects between GPS models and MWA observations
B. S. Arora, J. Morgan, S. M. Ord +56
We compare first order (refractive) ionospheric effects seen by the Murchison Widefield Array (MWA) with the ionosphere as inferred from Global Positioning System (GPS) data. The f…
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…