Stangalini, M., Jafarzadeh, S., Ermolli, I. et al. (7 more authors) (2018) Propagating spectropolarimetric disturbances in a large sunspot. Astrophysical Journal, 869 (2). 110. ISSN 0004-637X
Abstract
We present results derived from the analysis of spectropolarimetric measurements of active region AR12546, which represents one of the largest sunspots to have emerged onto the solar surface over the last 20 years. The region was observed with full-Stokes scans of the Fe I 617.3 nm and Ca II 854.2 nm lines with the Interferometric BIdimensional Spectrometer (IBIS) instrument at the Dunn Solar Telescope over an uncommon, extremely long time interval exceeding three hours. Clear circular polarization (CP) oscillations localized at the umbra-penumbra boundary of the observed region were detected. Furthermore, the multi-height data allowed us to detect the downward propagation of both CP and intensity disturbances at 2.5−3~mHz, which was identified by a phase delay between these two quantities. These results are interpreted as a propagating magneto-hydrodynamic surface mode in the observed sunspot.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 The American Astronomical Society. Reproduced in accordance with the publisher's self-archiving policy. |
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) |
Funding Information: | Funder Grant number SCIENCE AND TECHNOLOGY FACILITIES COUNCIL ST/M000826/1 ROYAL SOCIETY IE161153 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 07 Dec 2018 13:15 |
Last Modified: | 23 Jan 2019 15:31 |
Published Version: | https://doi.org/10.3847/1538-4357/aaec7b |
Status: | Published |
Publisher: | American Astronomical Society |
Refereed: | Yes |
Identification Number: | 10.3847/1538-4357/aaec7b |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:138419 |