Journal article


DL Kaplan, SJ Tingay, PK Manoharan, JP Macquart, P Hancock, J Morgan, DA Mitchell, RD Ekers, RB Wayth, C Trott, T Murphy, D Oberoi, IH Cairns, L Feng, N Kudryavtseva, G Bernardi, JD Bowman, F Briggs, RJ Cappallo, AA Deshpande Show all



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 30° × 30° Murchison Widefield Array (MWA) Epoch of Reionization fields using the MWA at 155 MHz. After rejecting intrinsic, instrumental, and ionospheric origins we consider the most likely explanation for this variability to be interplanetary scintillation (IPS), likely the result of a large coronal mass ejection propagating from the Sun. This is confirmed by roughly contemporaneous observations with the Ooty Radio Telescope. We see evidence for structure on spatial scales ranging from 106 km. The serendi..

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University of Melbourne Researchers


Awarded by U.S. National Science Foundation

Awarded by Australian Research Council (LIEF)

Awarded by U.S. Air Force Office of Scientific Research

Awarded by Centre for All-sky Astrophysics (an Australian Research Council Centre of Excellence)

Awarded by NSF

Awarded by Victoria University of Wellington from the New Zealand Ministry of Economic Development

Awarded by Direct For Mathematical & Physical Scien

Funding Acknowledgements

We thank an anonymous referee for a thorough and thoughtful review. We thank B. Jackson, C. Loi, and A. Rowlinson for helpful conversations. This scientific work makes use of the Murchison Radio-astronomy Observatory, operated by CSIRO. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. Support for the MWA comes from the U.S. National Science Foundation (grants AST-0457585, PHY-0835713, CAREER-0847753, and AST-0908884), the Australian Research Council (LIEF grants LE0775621 and LE0882938), the U.S. Air Force Office of Scientific Research (grant FA9550-0510247), and the Centre for All-sky Astrophysics (an Australian Research Council Centre of Excellence funded by grant CE110001020). D.L.K. is additionally supported by NSF grant AST-1412421. P.K.M. acknowledges partial support from ISRO. Support is also provided by the Smithsonian Astrophysical Observatory, the MIT School of Science, the Raman Research Institute, the Australian National University, and the Victoria University of Wellington (via grant MED-E1799 from the New Zealand Ministry of Economic Development and an IBM Shared University Research Grant). The Australian Federal government provides additional support via the Commonwealth Scientific and Industrial Research Organisation (CSIRO), National Collaborative Research Infrastructure Strategy, Education Investment Fund, and the Australia India Strategic Research Fund, and Astronomy Australia Limited, under contract to Curtin University. We acknowledge the iVEC Petabyte Data Store, the Initiative in Innovative Computing and the CUDA Center for Excellence sponsored by NVIDIA at Harvard University, and the International Centre for Radio Astronomy Research (ICRAR), a Joint Venture of Curtin University and The University of Western Australia, funded by the Western Australian State government. This research made use of APLpy, an open-source plotting package for Python hosted at