Allian, F. orcid.org/0000-0002-4569-0370, Jain, R. orcid.org/0000-0002-0080-5445 and Hindman, B.W. (2019) A new analysis procedure for detecting periodicities within complex solar coronal arcades. The Astrophysical Journal, 880 (3). ISSN 0004-637X
Abstract
We study intensity variations, as measured by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, in a solar coronal arcade using a newly developed analysis procedure that employs spatio-temporal autocorrelations. We test our new procedure by studying large-amplitude oscillations excited by nearby flaring activity within a complex arcade and detect a dominant periodicity of 12.31 minutes. We compute this period in two ways: from the traditional time–distance fitting method and using our new autocorrelation procedure. The two analyses yield consistent results. The autocorrelation procedure is then implemented on time series for which the traditional method would fail due to the complexity of overlapping loops and a poor contrast between the loops and the background. Using this new procedure, we discover the presence of small-amplitude oscillations within the same arcade with 9.13 and 9.81 minute periods prior and subsequent to the large-amplitude oscillations, respectively. Consequently, we identify these as "decayless" oscillations that have only been previously observed in nonflaring loop systems.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 The American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence (http://creativecommons.org/licenses/by/3.0). Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
Keywords: | Sun: activity; Sun: atmosphere; Sun: corona; Sun: flares; Sun: oscillations |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 07 Aug 2019 14:54 |
Last Modified: | 07 Aug 2019 14:54 |
Status: | Published |
Publisher: | IOP Publishing (American Astronomical Society) |
Refereed: | Yes |
Identification Number: | 10.3847/1538-4357/ab264c |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:149405 |