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Related papers: Strong ionospheric activity at the MWA site associ…

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Refraction and diffraction of incoming radio waves by the ionosphere induce time variability in the angular positions, peak amplitudes and shapes of radio sources, potentially complicating the automated cross-matching and identification of…

Geomagnetically-aligned density structures with a range of sizes exist in the near-Earth plasma environment, including 10-100 km-wide VLF/HF wave-ducting structures. Their small diameters and modest density enhancements make them difficult…

The Murchison Widefield Array (MWA) is a low-frequency aperture array capable of high-time and frequency resolution astronomy applications such as pulsar studies. The large field-of-view of the MWA (hundreds of square degrees) can also be…

Instrumentation and Methods for Astrophysics · Physics 2022-05-18 N. A. Swainston , N. D. R. Bhat , I. S. Morrison , S. J. McSweeney , S. M. Ord , S. E. Tremblay , M. Sokolowski

Structure imprinted in foreground extragalactic point sources by ionospheric refraction has the potential to contaminate Epoch of Reionisation (EoR) power spectra of the 21~cm emission line of neutral hydrogen. The alteration of the spatial…

We forecast the sensitivity with which the Murchison Widefield Array (MWA) can measure the 21 cm power spectrum of cosmic hydrogen, using radiative transfer simulations to model reionization and the 21 cm signal. The MWA is sensitive to…

Astrophysics · Physics 2009-11-13 Adam Lidz , Oliver Zahn , Matthew McQuinn , Matias Zaldarriaga , Lars Hernquist

We present and evaluate several strategies to search for prompt, low-frequency radio emission associated with gravitational wave transients using the Murchison Widefield Array (MWA). As we are able to repoint the MWA on timescales of tens…

Instrumentation and Methods for Astrophysics · Physics 2016-10-12 D. L. Kaplan , T. Murphy , A. Rowlinson , S. D. Croft , R. B. Wayth , C. M. Trott

The radio-wavelength detection of extensive air showers (EAS) initiated by cosmic-ray interactions in the Earth's atmosphere is a promising technique for investigating the origin of these particles and the physics of their interactions. The…

Instrumentation and Methods for Astrophysics · Physics 2021-03-29 A. Williamson , C. W. James , S. J. Tingay , S. J. McSweeney , S. M. Ord

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 wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionised radio astronomy. Despite their construction from static, relatively simple dipoles, the sheer…

Instrumentation and Methods for Astrophysics · Physics 2021-02-02 A. Chokshi , J. L. B. Line , N. Barry , D. Ung , D. Kenney , A. McPhail , A. Williams , R. L. Webster

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-Time System' (RTS). Using the high spatial- and…

Instrumentation and Methods for Astrophysics · Physics 2017-08-30 C. H. Jordan , S. Murray , C. M. Trott , R. B. Wayth , D. A. Mitchell , M. Rahimi , B. Pindor , P. Procopio , J. Morgan

We present a study of scintillation induced by the mid-latitude ionosphere. By implementing methods currently used in Interplanetary Scintillation studies to measure amplitude scintillation at low frequencies, we have proven it is possible…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 A. Waszewski , J. Morgan , C. H. Jordan

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…

Fast Radio Bursts (FRBs) are short timescale (<<1 s) astrophysical radio signals, presumed to be a signature of cataclysmic events of extragalactic origin. The discovery of six high-redshift events at ~1400 MHz from the Parkes radio…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Cathryn M. Trott , Steven J. Tingay , Randall B. Wayth

The Murchison Widefield Array (MWA) is an electronically steered low frequency ($<300$\,MHz) radio interferometer, with a `slew' time less than 8seconds. Low frequency ($\sim 100$\,MHz) radio telescopes are ideally suited for rapid-response…

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