Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism

We have developed a new coherent dedispersion mode to study the emission of fast radio bursts (FRBs) that trigger the voltage capture capability of the Australian SKA Pathfinder (ASKAP) interferometer. In principle the mode can probe emission timescales down to 3 ns with full polarimetric informatio...

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Main Authors: Cho, H., Macquart, Jean-Pierre, Shannon, Ryan, Deller, A.T., Morrison, Ian, Ekers, Ronald, Bannister, K.W., Farah, W., Qiu, H., Sammons, M.W., Bailes, M., Bhandari, S., Day, C.K., James, Clancy, Phillips, C.J., Prochaska, J.X., Tuthill, J.
Format: Journal Article
Language:English
Published: IOP PUBLISHING LTD 2020
Subjects:
Online Access:http://purl.org/au-research/grants/arc/DP180100857
http://hdl.handle.net/20.500.11937/91554
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author Cho, H.
Macquart, Jean-Pierre
Shannon, Ryan
Deller, A.T.
Morrison, Ian
Ekers, Ronald
Bannister, K.W.
Farah, W.
Qiu, H.
Sammons, M.W.
Bailes, M.
Bhandari, S.
Day, C.K.
James, Clancy
Phillips, C.J.
Prochaska, J.X.
Tuthill, J.
author_facet Cho, H.
Macquart, Jean-Pierre
Shannon, Ryan
Deller, A.T.
Morrison, Ian
Ekers, Ronald
Bannister, K.W.
Farah, W.
Qiu, H.
Sammons, M.W.
Bailes, M.
Bhandari, S.
Day, C.K.
James, Clancy
Phillips, C.J.
Prochaska, J.X.
Tuthill, J.
author_sort Cho, H.
building Curtin Institutional Repository
collection Online Access
description We have developed a new coherent dedispersion mode to study the emission of fast radio bursts (FRBs) that trigger the voltage capture capability of the Australian SKA Pathfinder (ASKAP) interferometer. In principle the mode can probe emission timescales down to 3 ns with full polarimetric information preserved. Enabled by the new capability, here we present a spectropolarimetric analysis of FRB 181112 detected by ASKAP, localized to a galaxy at redshift 0.47. At microsecond time resolution the burst is resolved into four narrow pulses with a rise time of just 15 μs for the brightest. The pulses have a diversity of morphology, but do not show evidence for temporal broadening by turbulent plasma along the line of sight, nor is there any evidence for periodicity in their arrival times. The pulses are highly polarized (up to 95%), with the polarization position angle varying both between and within pulses. The pulses have apparent rotation measures that vary by and apparent dispersion measures that vary by. Conversion between linear and circular polarization is observed across the brightest pulse. We conclude that the FRB 181112 pulses are most consistent with being a direct manifestation of the emission process or the result of propagation through a relativistic plasma close to the source. This demonstrates that our method, which facilitates high-time-resolution polarimetric observations of FRBs, can be used to study not only burst emission processes, but also a diversity of propagation effects present on the gigaparsec paths they traverse.
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spelling curtin-20.500.11937-915542023-05-16T07:20:46Z Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism Cho, H. Macquart, Jean-Pierre Shannon, Ryan Deller, A.T. Morrison, Ian Ekers, Ronald Bannister, K.W. Farah, W. Qiu, H. Sammons, M.W. Bailes, M. Bhandari, S. Day, C.K. James, Clancy Phillips, C.J. Prochaska, J.X. Tuthill, J. Science & Technology Physical Sciences Astronomy & Astrophysics POLARIZATION PROPAGATION PSRCHIVE PSRFITS astro-ph.HE astro-ph.HE We have developed a new coherent dedispersion mode to study the emission of fast radio bursts (FRBs) that trigger the voltage capture capability of the Australian SKA Pathfinder (ASKAP) interferometer. In principle the mode can probe emission timescales down to 3 ns with full polarimetric information preserved. Enabled by the new capability, here we present a spectropolarimetric analysis of FRB 181112 detected by ASKAP, localized to a galaxy at redshift 0.47. At microsecond time resolution the burst is resolved into four narrow pulses with a rise time of just 15 μs for the brightest. The pulses have a diversity of morphology, but do not show evidence for temporal broadening by turbulent plasma along the line of sight, nor is there any evidence for periodicity in their arrival times. The pulses are highly polarized (up to 95%), with the polarization position angle varying both between and within pulses. The pulses have apparent rotation measures that vary by and apparent dispersion measures that vary by. Conversion between linear and circular polarization is observed across the brightest pulse. We conclude that the FRB 181112 pulses are most consistent with being a direct manifestation of the emission process or the result of propagation through a relativistic plasma close to the source. This demonstrates that our method, which facilitates high-time-resolution polarimetric observations of FRBs, can be used to study not only burst emission processes, but also a diversity of propagation effects present on the gigaparsec paths they traverse. 2020 Journal Article http://hdl.handle.net/20.500.11937/91554 10.3847/2041-8213/ab7824 English http://purl.org/au-research/grants/arc/DP180100857 http://purl.org/au-research/grants/arc/FT190100155 http://purl.org/au-research/grants/arc/FL150100148 http://purl.org/au-research/grants/arc/CE170100004 http://purl.org/au-research/grants/arc/FT150100415 IOP PUBLISHING LTD fulltext
spellingShingle Science & Technology
Physical Sciences
Astronomy & Astrophysics
POLARIZATION
PROPAGATION
PSRCHIVE
PSRFITS
astro-ph.HE
astro-ph.HE
Cho, H.
Macquart, Jean-Pierre
Shannon, Ryan
Deller, A.T.
Morrison, Ian
Ekers, Ronald
Bannister, K.W.
Farah, W.
Qiu, H.
Sammons, M.W.
Bailes, M.
Bhandari, S.
Day, C.K.
James, Clancy
Phillips, C.J.
Prochaska, J.X.
Tuthill, J.
Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism
title Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism
title_full Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism
title_fullStr Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism
title_full_unstemmed Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism
title_short Spectropolarimetric Analysis of FRB 181112 at Microsecond Resolution: Implications for Fast Radio Burst Emission Mechanism
title_sort spectropolarimetric analysis of frb 181112 at microsecond resolution: implications for fast radio burst emission mechanism
topic Science & Technology
Physical Sciences
Astronomy & Astrophysics
POLARIZATION
PROPAGATION
PSRCHIVE
PSRFITS
astro-ph.HE
astro-ph.HE
url http://purl.org/au-research/grants/arc/DP180100857
http://purl.org/au-research/grants/arc/DP180100857
http://purl.org/au-research/grants/arc/DP180100857
http://purl.org/au-research/grants/arc/DP180100857
http://purl.org/au-research/grants/arc/DP180100857
http://hdl.handle.net/20.500.11937/91554