Quasi-periodic pulsations in a solar flare with an unusual phase shift
| Autor: | L. K. Kashapova, Abhishek K. Srivastava, Yong-Jae Moon, Partha Chowdhury, Elena G. Kupriyanova, Tom Van Doorsselaere |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
corona [Sun]
Astrophysics::High Energy Astrophysical Phenomena WAVES Phase (waves) FOS: Physical sciences Astronomy & Astrophysics 01 natural sciences ACOUSTIC-OSCILLATIONS law.invention ENERGY law 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics X-rays gamma-rays [Sun] 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Physics UV radiation [Sun] Science & Technology Solar flare 010308 nuclear & particles physics radio radiation [Sun] Relaxation (NMR) Gamma ray Astronomy and Astrophysics DECAY PHASE Computational physics flares [Sun] Amplitude Moreton wave Astrophysics - Solar and Stellar Astrophysics EVENT Space and Planetary Science Extreme ultraviolet Physical Sciences Flare |
| Zdroj: | Monthly Notices of the Royal Astronomical Society |
| ISSN: | 5499-5507 |
| Popis: | © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. Two kinds of processes could occur during the flare decay phase: processes of energy release or processes of energy relaxation. Quasi-periodic pulsations (QPPs) of the broad-band emission are a good tool for the verification of mechanisms. We aim to study the processes during the decay phase of the X-class solar flare SOL2014-03-29T17:48. The observations in X-ray, microwave, and extreme ultraviolet bands are exploited to study the fine temporal, spatial, and spectral structures of the flare. The periods, amplitudes, and phases of both the fluxes and physical parameters [emission measure (EM), temperature] are studied using standard methods of correlation, Fourier, and wavelet analyses. It is found that the source of the QPPs is associated with the uniform post-flare loop. The X-ray source is located at the top of the arcade. QPPs with the similar characteristic time scales of P ≈ 74-80 s are found in the X-ray (3-25 keV) and microwave (15.7 GHz) emissions. Besides, QPPs with the same period are found in the time profiles of both the temperature (T e) and EM. The QPPs in temperature and the QPPs in EM demonstrate antiphase behaviour. The analysis reveals the quasi-periodic process of energy relaxation, without any additional source of energy during the decay phase. The periods of the QPPs are in a good agreement with second harmonic of standing slow magneto-acoustic wave in the arcade that could be triggered by a Moreton wave initiated by the flare in the direct vicinity of the arcade. ispartof: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY vol:483 issue:4 pages:5499-5507 status: published |
| Databáze: | OpenAIRE |
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