Coronal Fourier power spectra: implications for coronal seismology and coronal heating

Abstract

The dynamics of regions of the solar corona are investigated using Atmospheric Imaging Assembly (AIA) 171Å and 193Å data. The coronal emission from the quiet Sun, coronal loop footprints, coronal moss, and from above a sunspot is studied. It is shown that the mean Fourier power spectra in these regions can be described by a power law at lower frequencies that tails to flat spectrum at higher frequencies, plus a Gaussian-shaped contribution that varies depending on the region studied. This Fourier spectral shape is in contrast to the commonly-held assumption that coronal time-series are well described by the sum of a long time-scale background trend plus Gaussian-distributed noise, with some specific locations also showing an oscillatory signal. The implications of this discovery to the field of coronal seismology and the automated detections of oscillations are discussed. The power law contribution to the shape of the Fourier power spectrum is interpreted as being due to the summation of a distribution of exponentially decaying emission events along the line of sight. This is consistent with the idea that the solar atmosphere is heated everywhere by small energy deposition events.

References in corpus (20)

• scikit-image: Image processing in Python
• Information criteria for astrophysical model selection
• On Solving the Coronal Heating Problem
• The stellar atmosphere simulation code Bifrost
• MHD Waves and Coronal Seismology: an overview of recent results
• Highly Efficient Modeling of Dynamic Coronal Loops
• A Bayesian test for periodic signals in red noise
• Observing coronal nanoflares in active region moss
• Quasi-periodic Propagating Signals in the Solar Corona: The Signature of Magnetoacoustic Waves or High-Velocity Upflows?
• Enthalpy-based Thermal Evolution of Loops: II. Improvements to the Model
• The Spectroscopic Signature of Quasi-periodic Upflows in Active Region Timeseries
• Long-period intensity pulsations in the solar corona during activity cycle 23
• Forward modeling of emission in SDO/AIA passbands from dynamic 3D simulations
• Evidence of Shock-Driven Turbulence in the Solar Chromosphere
• Application of the Information Criterion to the Estimation of Galaxy Luminosity Function
• High-Frequency Oscillations in a Solar Active Region observed with the Rapid Dual Imager
• Observations of Dissipation of Slow Magneto-acoustic Waves in a Polar Coronal Hole
• Estimating the properties of hard X-ray solar flares by constraining model parameters
• A Coherence-Based Approach for Tracking Waves in the Solar Corona
• Automated Detection of Oscillating Regions in the Solar Atmosphere

Cited by in corpus (33)

• Observations of Turbulent Magnetic Reconnection Within a Solar Current Sheet
• Quasi-periodic pulsations in solar and stellar flares: an overview of recent results
• Soft X-ray Pulsations in Solar Flares
• A large-scale search for evidence of quasi-periodic pulsations in solar flares
• On The Fourier And Wavelet Analysis Of Coronal Time Series
• The Coronal Monsoon: Thermal Nonequilibrium Revealed by Periodic Coronal Rain
• 25 Years of Self-Organized Criticality: Numerical Detection Methods
• Statistical Signatures of Nanoflare Activity. I. Monte Carlo Simulations and Parameter-space Exploration
• Observations of solar chromospheric oscillations at 3 mm with ALMA
• Effects of flare definitions on the statistics of derived flare distributions
• Motion magnification in coronal seismology
• Temperature of Solar Orbiter/EUI quiet Sun small scale brightenings: evidence for a cooler component
• Novel data analysis techniques in coronal seismology
• Thermal non-equilibriuem revealed by periodic pulses of random amplitudes in solar coronal loops
• Pitfalls of periodograms: The non-stationarity bias in the analysis of quasi-periodic oscillations
• Propagation of Waves above a Plage as Observed by IRIS and SDO
• A Statistical Study on The Frequency-Dependent Damping of Slow-mode Waves in Polar Plumes and Interplumes
• A study of sunspot 3 minute oscillations using ALMA and GST
• Oscillation of solar radio emission at coronal acoustic cut-off frequency
• Spatial Distributions of Sunspot Oscillation Modes at Different Temperatures
• Damping and power spectra of quasi-periodic intensity disturbances above a solar polar coronal hole
• Do Periods of Decayless Kink Oscillations of Solar Coronal Loops Depend on Noise?
• Radio, EUV, and X-Ray Observations During a Filament Rise in the 2011 June 7 Solar Flare
• Implications of spicule activity on coronal loop heating and catastrophic cooling
• A Global Survey of EUV Corona Power Spectra
• Comparison of the Scaling Properties of EUV Intensity Fluctuations in Coronal Hole and Quiet-Sun Regions
• Multifractal Solar EUV Intensity Fluctuations and their Implications for Coronal Heating Models
• Quasi-periodic Fast-mode Magnetosonic Wave Trains Within Coronal Waveguides Associated with Flares and CMEs
• Do Cellular Automaton Avalanche Models Simulate the Quasi-Periodic Pulsations of Solar Flares?
• The need for new techniques to identify the high-frequency MHD waves of an oscillating coronal loop
• Solar slow magneto-acoustic-gravity waves: an erratum correction and a revisited scenario
• Power-law Indices of EUV Intensity Power Spectrum in Flaring Coronal Active Regions
• Wide-band fluctuations of solar active regions probed with SHARP magnetograms