English
Related papers

Related papers: Low Frequency Imaging of Fields at High Galactic L…

200 papers

We detail and present results from a pilot study to assess the feasibility of detecting molecular lines at low radio frequencies. We observed a 400 square degree region centred on the Galactic Centre with the Murchison Widefield Array (MWA)…

Deep imaging of structures from the Cosmic Dawn (CD) and the Epoch of Reionization (EoR) in five targeted fields is one of the highest priority scientific objectives for the Square Kilometre Array (SKA). Selecting 'quiet' fields, which…

Instrumentation and Methods for Astrophysics · Physics 2025-07-14 Xueying Zhang , Qian Zheng , Linhui Wu , Quan Guo , Stefan W. Duchesne , Mengfan He , Huanyuan Shan , Xiang-ping Wu , Melanie Johnston-Hollitt , Feiyu Zhao , Qingyuan Ma

Our previously reported survey of the Low Earth Orbit (LEO) environment using the Murchison Widefield Array (MWA) detected over 70 unique Resident Space Objects (RSOs) over multiple passes, from 20 hours of observations in passive radar…

Instrumentation and Methods for Astrophysics · Physics 2022-07-20 Steve Prabu , Paul J Hancock , Xiang Zhang , Steven J Tingay , Torrance Hodgson , Brian Crosse , Melanie Johnston-Hollitt

We describe the motivation and design details of the "Phase II" upgrade of the Murchison Widefield Array (MWA) radio telescope. The expansion doubles to 256 the number of antenna tiles deployed in the array. The new antenna tiles enhance…

At relatively high frequencies, highly sensitive grating sidelobes occur in the primary beam patterns of low frequency aperture arrays (LFAA) such as the Murchison Widefield Array (MWA). This occurs when the observing wavelength becomes…

Instrumentation and Methods for Astrophysics · Physics 2021-04-05 J. H. Cook , N. Seymour , M. Sokolowski

It has been proposed that coherent radio emission could be emitted during or shortly following a gamma-ray burst (GRB). Here we present a low-frequency ($170-200$ MHz) search for radio pulses associated with long-duration GRBs using the…

A host of new low-frequency radio telescopes seek to measure the 21-cm transition of neutral hydrogen from the early universe. These telescopes have the potential to directly probe star and galaxy formation at redshifts $20 \gtrsim z…

We present observations of high-amplitude rapid (2 s) variability toward two bright, compact extragalactic radio sources out of several hundred of the brightest radio sources in one of the 30x30 deg MWA Epoch of Reionization fields using…

The Earth's ionosphere refracts radio signals, shifting the apparent position of radio sources. Wide-field measurements with a radio interferometer can measure the ionospheric distortion. The Murchison Widefield Array (MWA) has the ability…

We present the first dedicated observations of Interplanetary Scintillation (IPS) with the Murchison Widefield Array (MWA). We have developed a synthesis imaging technique, tailored to the properties of modern "large-N" low-frequency radio…

Instrumentation and Methods for Astrophysics · Physics 2017-09-12 J . S. Morgan , J-P. Macquart , R. Ekers , R. Chhetri , M. Tokumaru , P. K. Manoharan , S. Tremblay , M. M. Bisi , B. V. Jackson

Calibration of instrumental polarization is critical for measuring polarized radio emissions from astrophysical sources to extract the magnetic field information in astrophysical, heliospheric, and terrestrial plasmas. At meter wavelengths,…

Instrumentation and Methods for Astrophysics · Physics 2025-05-08 Devojyoti Kansabanik , Angelos Vourlidas , Soham Dey , Surajit Mondal , Divya Oberoi

The Murchison Widefield Array (MWA) is a next-generation radio telescope, generating visibility data products continuously at about 400 MB/s. Efficiently managing and archiving this data is a challenge. The MWA Archive consists of dataflows…

Instrumentation and Methods for Astrophysics · Physics 2013-08-29 Chen Wu , Andreas Wicenec , Dave Pallot , Alessio Checcucci

We characterize the low frequency radio-frequency interference (RFI) environment at the Murchison Radio-astronomy Observatory (MRO), the location selected for the low-frequency component of the Square Kilometre Array. Data were collected…

Instrumentation and Methods for Astrophysics · Physics 2018-11-07 Marcin Sokolowski , Randall B. Wayth , Morgan Lewis

Electron density irregularities in the ionosphere are known to be magnetically anisotropic, preferentially elongated along the lines of force. While many studies of their morphology have been undertaken by topside sounding and whistler…

Imaging the low-frequency radio Sun is an intrinsically challenging problem. Meter-wavelength solar emission spans angular scales from a few arcminutes to a few degrees. These emissions show temporal and spectral variability on a sub-second…

Solar and Stellar Astrophysics · Physics 2022-09-22 Devojyoti Kansabanik

Around 10% of bright low-frequency radio sources observed with the Murchison Widefield Array (MWA) show strong Interplanetary Scintillation (IPS) on timescales of a few seconds, implying that almost all their low-frequency radio emission…

Astrophysics of Galaxies · Physics 2018-11-28 Elaine M. Sadler , Rajan Chhetri , John Morgan , Elizabeth K. Mahony , Thomas H. Jarrett , Steven Tingay

We follow up on a report by Vacca et al. (2018) of 28 candidate large-scale diffuse synchrotron sources in an 8{\deg}$\times$8{\deg} area of the sky (centred at RA 5h0m0s Dec 5{\deg}48'0''). These sources were originally observed at 1.4 GHz…

Astrophysics of Galaxies · Physics 2022-05-27 Torrance Hodgson , Melanie Johnston-Hollitt , Benajmin McKinley , Tessa Vernstrom , Valentina Vacca

Polarimetric studies of pulsars at low radio frequencies provide important observational insights into the pulsar emission mechanism and beam models, and probe the properties of the magneto-ionic interstellar medium (ISM). Aperture arrays…

High Energy Astrophysical Phenomena · Physics 2019-08-07 Mengyao Xue , S. M. Ord , S. E. Tremblay , N. D. R. Bhat , C. Sobey , B. W. Meyers , S. J. McSweeney , N. A. Swainston

The Murchison Widefield Array is a low-frequency Square Kilometre Array precursor located at the Murchison Radio-astronomy Observatory in Western Australia. Primarily designed as an imaging telescope, but with a flexible signal path, the…

Instrumentation and Methods for Astrophysics · Physics 2019-08-15 S. M. Ord , S. E. Tremblay , S. J. McSweeney , N. D. R. Bhat , C. Sobey , D. A. Mitchell , P. J. Hancock , F. Kirsten

We provide the first in situ measurements of antenna element (tile) beam shapes of the Murchison Widefield Array (MWA), a low radio-frequency interferometer and an SKA precursor. Most current MWA processing pipelines use an assumed beam…