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Published July 21, 2018 | Erratum + Accepted Version + Published
Journal Article Open

FRB microstructure revealed by the real-time detection of FRB170827

Abstract

We report a new fast radio burst (FRB) discovered in real-time as part of the UTMOST project at the Molonglo Observatory Synthesis Radio Telescope. FRB170827 was first detected with our low-latency (<24 s) and machine-learning based FRB detection system. The FRB discovery was accompanied by the capture of voltage data at the native time and frequency resolution of the observing system, enabling coherent dedispersion and detailed off-line analysis that have unveiled fine temporal and frequency structure. The dispersion measure (DM) of 176.80 ± 0.04 pc cm^(−3) is the lowest of the FRB population. The Milky Way contribution along the line of sight is ∼40 pc cm^(−3), leaving an excess DM of ∼145 pc cm^(−3). The FRB has a fluence >20 ± 7 Jy ms, and is narrow with a width of ∼400 s at 10 per cent of its maximum amplitude. However, the burst shows three temporal components, the narrowest of which is ∼30 s, and a scattering time-scale of 4.1 ± 2.7 s. The FRB shows spectral modulations on frequency scales of 1.5 MHz and 0.1 MHz. Both are prominent in the dynamic spectrum, which shows a very bright region of emission between 841 and 843 MHz, and weaker and patchy emission across the entire band. We show that the fine spectral structure could arise in the FRB host galaxy, or its immediate vicinity.

Additional Information

© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices). Accepted 2018 April 21. Received 2018 April 20; in original form 2018 March 7. Published: 03 May 2018. The authors would like to thank the anonymous referee for useful comments and suggestions. The Molonglo Observatory is owned and operated by the University of Sydney, with support from the School of Physics and the University. The UTMOST project is also supported by the Swinburne University of Technology. We acknowledge the Australian Research Council grants CE110001020 (Australian Research Council Centre of Excellence for All-Sky Astrophysics, CAASTRO) and the Laureate Fellowship FL150100148. We thank Dave Temby, Glen Torr, Glenn Urquhart, and Simon Jordan for cheerfully keeping the UTMOST facility performing so smoothly. We thank Kiyoshi Masui for helpful discussions. The Parkes radio telescope is part of the Australia Telescope National Facility that is funded by the Commonwealth of Australia for operation as a National Facility managed by Commonwealth Scientific and Industrial Research Organisation (CSIRO). The Australian Square Kilometer Array Pathfinder (ASKAP) is part of the Australia Telescope National Facility that is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. ATD is supported by an ARC Future Fellowship grant FT150100415. Parts of this work was performed on the gSTAR national facility at Swinburne University of Technology. SkyMapper is owned and operated by The Australian National University's Research School of Astronomy and Astrophysics. The national facility capability for SkyMapper has been funded through the Australian Research Council LIEF grant LE130100104, awarded to the University of Sydney, the Australian National University, Swinburne University of Technology, the University of Queensland, the University of Western Australia, the University of Melbourne, Curtin University of Technology, Monash University, and the Australian Astronomical Observatory. MC acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 694745).

Attached Files

Published - sty1122.pdf

Accepted Version - 1803.05697.pdf

Erratum - sty3411.pdf

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Additional details

Created:
August 19, 2023
Modified:
October 23, 2023