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Title: Detection and Interpretation of Long-lived X-Ray Quasi-periodic Pulsations in the X-class Solar Flare on 2013 May 14

Abstract

Quasi-periodic pulsations (QPP) seen in the time derivative of the GOES soft X-ray light curves are analyzed for the X3.2 event on 2013 May 14. The pulsations are apparent for a total of at least two hours from the impulsive phase to well into the decay phase, with a total of 163 distinct pulses evident to the naked eye. A wavelet analysis shows that the characteristic timescale of these pulsations increases systematically from ∼25 s at 01:10 UT, the time of the GOES peak, to ∼100 s at 02:00 UT. A second “ridge” in the wavelet power spectrum, most likely associated with flaring emission from a different active region, shows an increase from ∼40 s at 01:40 UT to ∼100 s at 03:10 UT. We assume that the QPP that produced the first ridge result from vertical kink-mode oscillations of the newly formed loops following magnetic reconnection in the coronal current sheet. This allows us to estimate the magnetic field strength as a function of altitude given the density, loop length, and QPP timescale as functions of time determined from the GOES light curves and Ramaty High Energy Solar Spectroscopic Imager ( RHESSI ) images. The calculated magnetic field strengthmore » of the newly formed loops ranges from ∼500 G at an altitude of 24 Mm to a low value of ∼10 G at 60 Mm, in general agreement with the expected values at these altitudes. Fast sausage-mode oscillations are also discussed and cannot be ruled out as an alternate mechanism for producing the QPP.« less

Authors:
; ; ; ; ;  [1];  [2];  [3]
  1. Solar Physics Laboratory, Code 671, Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  2. ADNET Systems, Inc. at NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  3. School of Physics, Trinity College Dublin, Dublin 2 (Ireland)
Publication Date:
OSTI Identifier:
22663834
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 836; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALTITUDE; DETECTION; EMISSION; GAMMA RADIATION; MAGNETIC FIELDS; MAGNETIC RECONNECTION; OSCILLATION MODES; PERIODICITY; PULSATIONS; SOFT X RADIATION; SOLAR FLARES; SPECTRA; SUN; TIME DEPENDENCE; VISIBLE RADIATION

Citation Formats

Dennis, Brian R., Tolbert, Anne K., Inglis, Andrew, Ireland, Jack, Wang, Tongjiang, Holman, Gordon D., Hayes, Laura A., and Gallagher, Peter T., E-mail: brian.r.dennis@nasa.gov. Detection and Interpretation of Long-lived X-Ray Quasi-periodic Pulsations in the X-class Solar Flare on 2013 May 14. United States: N. p., 2017. Web. doi:10.3847/1538-4357/836/1/84.
Dennis, Brian R., Tolbert, Anne K., Inglis, Andrew, Ireland, Jack, Wang, Tongjiang, Holman, Gordon D., Hayes, Laura A., & Gallagher, Peter T., E-mail: brian.r.dennis@nasa.gov. Detection and Interpretation of Long-lived X-Ray Quasi-periodic Pulsations in the X-class Solar Flare on 2013 May 14. United States. doi:10.3847/1538-4357/836/1/84.
Dennis, Brian R., Tolbert, Anne K., Inglis, Andrew, Ireland, Jack, Wang, Tongjiang, Holman, Gordon D., Hayes, Laura A., and Gallagher, Peter T., E-mail: brian.r.dennis@nasa.gov. Fri . "Detection and Interpretation of Long-lived X-Ray Quasi-periodic Pulsations in the X-class Solar Flare on 2013 May 14". United States. doi:10.3847/1538-4357/836/1/84.
@article{osti_22663834,
title = {Detection and Interpretation of Long-lived X-Ray Quasi-periodic Pulsations in the X-class Solar Flare on 2013 May 14},
author = {Dennis, Brian R. and Tolbert, Anne K. and Inglis, Andrew and Ireland, Jack and Wang, Tongjiang and Holman, Gordon D. and Hayes, Laura A. and Gallagher, Peter T., E-mail: brian.r.dennis@nasa.gov},
abstractNote = {Quasi-periodic pulsations (QPP) seen in the time derivative of the GOES soft X-ray light curves are analyzed for the X3.2 event on 2013 May 14. The pulsations are apparent for a total of at least two hours from the impulsive phase to well into the decay phase, with a total of 163 distinct pulses evident to the naked eye. A wavelet analysis shows that the characteristic timescale of these pulsations increases systematically from ∼25 s at 01:10 UT, the time of the GOES peak, to ∼100 s at 02:00 UT. A second “ridge” in the wavelet power spectrum, most likely associated with flaring emission from a different active region, shows an increase from ∼40 s at 01:40 UT to ∼100 s at 03:10 UT. We assume that the QPP that produced the first ridge result from vertical kink-mode oscillations of the newly formed loops following magnetic reconnection in the coronal current sheet. This allows us to estimate the magnetic field strength as a function of altitude given the density, loop length, and QPP timescale as functions of time determined from the GOES light curves and Ramaty High Energy Solar Spectroscopic Imager ( RHESSI ) images. The calculated magnetic field strength of the newly formed loops ranges from ∼500 G at an altitude of 24 Mm to a low value of ∼10 G at 60 Mm, in general agreement with the expected values at these altitudes. Fast sausage-mode oscillations are also discussed and cannot be ruled out as an alternate mechanism for producing the QPP.},
doi = {10.3847/1538-4357/836/1/84},
journal = {Astrophysical Journal},
number = 1,
volume = 836,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2017},
month = {Fri Feb 10 00:00:00 EST 2017}
}
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