Author ORCID Identifier
James McAteer:
https://orcid.org/0000-0003-1493-101X
Anew Inglis:
https://orcid.org/0000-0003-0656-2437
Document Type
Journal Article
Journal Article Version
Final Version / Publisher's PDF (peer-reviewed)
Publication Date
1-1-2015
Abstract
The dynamics of regions of the solar corona are investigated using Atmospheric Imaging Assembly 171 angstrom and 193 angstrom 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.
Published in
Astrophysical Journal
DOI
10.1088/0004-637X/798/1/1
Keywords
Sun: oscillations, methods: data analysis, methods: statistical, Sun: corona
Department / Organizational Unit
Astronomy
Copyright Notice
© 2015 J. Ireland, R. McAteer, & A. Inglis, reuse allowed according to Creative Commons license.
License for Reuse
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Ireland, J., McAteer, R. T. J., & Inglis, A. R. (2015). Coronal Fourier power spectra: Implications for coronal seismology and coronal heating. Astrophysical Journal, 798(1). https://doi.org/10.1088/0004-637X/798/1/1