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 near-limb X3.2 event on 14 May 2013. 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 time scale of these pulsations increases systematically from $\sim$25 s at 01:10 UT, the time of the GOES peak, to $\sim$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 $\sim$40 s at 01:40 UT to $\sim$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 time scale as functions of time determined from the GOES light curves and RHESSI images. The calculated magnetic field strength of the newly formed loops ranges from about $\sim$500 G at an altitude of 24 Mm to a low value of $\sim$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.

References in corpus (5)

• Soft X-ray Pulsations in Solar Flares
• A large-scale search for evidence of quasi-periodic pulsations in solar flares
• Quasi-periodic pulsations in solar and stellar flares: re-evaluating their nature in the context of power-law flare Fourier spectra
• Quasi-Periodic Pulsations during the Impulsive and Decay phases of an X-class Flare
• Standing sausage modes in coronal loops with plasma flow

Cited by in corpus (16)

• Persistent Quasi-Periodic Pulsations During a Large X-Class Solar Flare
• Statistical Study of GOES X-ray Quasi-Periodic Pulsations in Solar Flares
• Detection of 3-Minute Oscillations in Full-Disk Ly$\alpha$ Emission During A Solar Flare
• Quasi-Periodic Particle Acceleration in a Solar Flare
• Preflare very long-periodic pulsations observed in Halpha emission before the onset of a solar flare
• Properties of quasi-periodic pulsations in solar flares from a single active region
• The direct relation between the duration of magnetic reconnection and the evolution of GOES light curves in solar flares
• Localising pulsations in the hard X-ray and microwave emission of an X-class flare
• Quasi-periodic pulsations in a solar flare with an unusual phase shift
• Localizing quasi-periodic pulsations in hard X-ray, microwave and Lya emissions of an X6.4 Flare
• Prevalence of non-stationarity in quasi-periodic pulsations (QPPs) associated with M- and X-class solar flares
• Do Cellular Automaton Avalanche Models Simulate the Quasi-Periodic Pulsations of Solar Flares?
• Spatial and temporal analysis of 3-minute oscillations in the chromosphere associated with the X2.2 Solar Flare on 2011 February 15
• The periodicity of three-dimensional oscillatory reconnection
• Quasi-Periodic Pulsations Detected in Ly$\alpha$ and Nonthermal Emissions During Solar Flares
• Time-dependent Turbulent Electron Acceleration and Transport in Solar Flares