Inferring the Coronal Density Irregularity from EUV Spectra
arXiv:1606.06247 · doi:10.3847/0004-637X/829/1/42
Abstract
Understanding the density structure of the solar corona is important for modeling both coronal heating and the solar wind. Direct measurements are difficult because of line-of-sight integration and possible unresolved structures. We present a new method for quantifying such structure using density-sensitive EUV line intensities to derive a density irregularity parameter, a relative measure of the amount of structure along the line of sight. We also present a simple model to relate the inferred irregularities to physical quantities, such as the filling factor and density contrast. For quiet Sun regions and interplume regions of coronal holes, we find a density contrast of at least a factor of three to ten and corresponding filling factors of about 10-20%. Our results are in rough agreement with other estimates of the density structures in these regions. The irregularity diagnostic provides a useful relative measure of unresolved structure in various regions of the corona.
Submitted to the Astrophysical Journal
References in corpus (8)
- Self-consistent Coronal Heating and Solar Wind Acceleration from Anisotropic Magnetohydrodynamic Turbulence
- CHIANTI - An atomic database for Emission Lines. Version 8
- High precision density measurements in the solar corona: I. Analysis methods and results for Fe XII and Fe XIII
- Heating and Acceleration of the Fast Solar Wind by Alfvén Wave Turbulence
- Spectroscopic signature of Alfvén waves damping in a polar coronal hole up to 0.4 solar radii
- The Solar Corona as probed by Comet Lovejoy (C/2011 W3)
- Evidence for Wave Heating of the Quiet Sun Corona
- Relative Abundance Measurements in Plumes and Interplumes