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Title: CORONAL FOURIER POWER SPECTRA: IMPLICATIONS FOR CORONAL SEISMOLOGY AND CORONAL HEATING

The dynamics of regions of the solar corona are investigated using Atmospheric Imaging Assembly 171 Å and 193 Å 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 a 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 timescale background trend plus Gaussian-distributed noise, with some specific locations also showing an oscillatory signal. The implications of the observed spectral shape on the fields of coronal seismology and the automated detection of oscillations in the corona 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.
Authors:
 [1] ;  [2] ;  [3]
  1. ADNET Systems, Inc., NASA Goddard Space Flight Center, MC. 671.1, Greenbelt, MD 20771 (United States)
  2. Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)
  3. NASA Goddard Space Flight Center, Greenbelt, MC. 671.1, MD 20771 (United States)
Publication Date:
OSTI Identifier:
22364780
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 798; 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; DATA ANALYSIS; DETECTION; ENERGY ABSORPTION; ENERGY LOSSES; HEATING; NOISE; OSCILLATIONS; SEISMOLOGY; SIGNALS; SOLAR CORONA; SUN; SUNSPOTS