Understand spectroheliograms - insight from spectral line analysis
Abstract
In an effort to seek newer diagnostic tools for monitoring the solar activity, we have reconstructed spectroheliograms in various spectral lines in the range 3900-3940 Angstroms (around the Ca II K line), from high spatial and spectral resolution measurements. In active regions, we find that the spectroheliogram features in a number of spectral lines are similar to the Ca II K1v spectroheliogram features. In plages, on the contrary, only spectroheliograms in a few spectral lines correlate with the Ca II K1v. In plages, we get the best correlation with the Si I 3905. From these measurements we develop contrast functions to isolate various active phenomena as seen in Ca II, and compare its formation contribution of relative velocities, magnetic fields and intensity as seen in Fe I and Si I spectral lines. These indicators provide much insight into the formation of Ca II K line.
- Publication:
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Memorie della Societa Astronomica Italiana
- Pub Date:
- 2001
- Bibcode:
- 2001MmSAI..72..553S
- Keywords:
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- Spectroheliograms;
- Solar Activity