The Library
Quasi-periodic pulsations in a solar microflare
Tools
Tools
Tools
Nakariakov, V. M. (Valery M.), Anfinogentov, S., Storozhenko, A. A., Kurochkin, E. A., Bogod, V. M., Sharykin, I. N. and Kaltman, T. I. (2018) Quasi-periodic pulsations in a solar microflare. The Astrophysical Journal, 859 (2). 154. doi:10.3847/1538-4357/aabfb9 ISSN 1538-4357.
|
PDF
WRAP-quasi-perodic-pulsations-solar-Nakariakov-2018.pdf - Published Version - Requires a PDF viewer. Download (3173Kb) | Preview |
Official URL: https://doi.org/10.3847/1538-4357/aabfb9
Abstract
Irregular time evolution of the radio emission generated in a B2-class microflare (SOL2017-01-25T10:15), occurring on 2017 January 25 in active region 12,628, is studied. The microflare was apparently initiated by an appearance of an s-shaped loop, observed in the EUV band. The radio emission is associated with the nonthermal electrons detected with Ramaty High Energy Solar Spectroscopic Imager, and originates simultaneously from two opposite footpoints of a magnetic fan structure beginning at a sunspot. According to the active region geometry, the footpoints are situated in the meridional direction, and hence are observed by RATAN-600 simultaneously. The radio emission intensity signal, as well as the left-hand and right-hand circular polarization signals in the low-frequency band (3–4 GHz) show good correlation with each other, with the average characteristic time of the variation 1.4 ± 0.3 s. The polarization signal shows a time variation with the characteristic time of about 0.7 ± 0.2 s. The irregular quasi-periodic pulsations of the radio emission are likely to be caused by the superposition of the signals generated at the local electron plasma frequencies by the interaction of nonthermal electrons with the plasma at the footpoints. In this scenario, the precipitation rate of the nonthermal electrons at the opposite footpoints could be modulated by the superposition of fundamental and second harmonic modes of sausage oscillations, resulting in the observed different characteristic times of the intensity and polarization signals. However, other mechanisms, e.g., the oscillatory regime of loop coalescence or magnetic null point oscillation could not be rigorously excluded.
| Item Type: | Journal Article | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Subjects: | Q Science > QB Astronomy | ||||||||||||||||||
| Divisions: | Faculty of Science, Engineering and Medicine > Science > Physics | ||||||||||||||||||
| SWORD Depositor: | Library Publications Router | ||||||||||||||||||
| Library of Congress Subject Headings (LCSH): | Solar flares, Sun -- Corona, Solar oscillations | ||||||||||||||||||
| Journal or Publication Title: | The Astrophysical Journal | ||||||||||||||||||
| Publisher: | American Astronomical Society | ||||||||||||||||||
| ISSN: | 1538-4357 | ||||||||||||||||||
| Official Date: | 4 June 2018 | ||||||||||||||||||
| Dates: |
|
||||||||||||||||||
| Volume: | 859 | ||||||||||||||||||
| Number: | 2 | ||||||||||||||||||
| Article Number: | 154 | ||||||||||||||||||
| DOI: | 10.3847/1538-4357/aabfb9 | ||||||||||||||||||
| Status: | Peer Reviewed | ||||||||||||||||||
| Publication Status: | Published | ||||||||||||||||||
| Reuse Statement (publisher, data, author rights): | © 2018. The American Astronomical Society. All rights reserved. | ||||||||||||||||||
| Access rights to Published version: | Restricted or Subscription Access | ||||||||||||||||||
| Copyright Holders: | The American Astronomical Society | ||||||||||||||||||
| Date of first compliant deposit: | 9 August 2018 | ||||||||||||||||||
| Date of first compliant Open Access: | 9 August 2018 | ||||||||||||||||||
| RIOXX Funder/Project Grant: |
|
||||||||||||||||||
| Related URLs: |
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
Downloads
Downloads per month over past year
