Coherence Analysis of Granular Intensity
Abstract
A high resolution spectrogram of the Mg b2 line from the quiet Sun disc centre is subjected to a coherence analysis. We find that the coherence between intensity fluctuations in the continuum and the wings of the line breaks down at a distance Δλ = 0.35 Å from line centre. From this and the r.m.s. intensity contrast as a function of Δλ we are led to the following simple model of temperature fluctuation δT in the solar photosphere: A lower part (below 50 km, or τ5000 > 0.25) with strongly inward increasing δT and an upper part (above 50 km) with constant δT = 75 K. The two parts are supposed to fluctuate incoherently.
- Publication:
-
Solar Physics
- Pub Date:
- November 1980
- DOI:
- 10.1007/BF00153264
- Bibcode:
- 1980SoPh...68...31K
- Keywords:
-
- Luminous Intensity;
- Photosphere;
- Solar Atmosphere;
- Solar Granulation;
- Solar Spectra;
- Spectrum Analysis;
- Atomic Spectra;
- Coherence;
- Correlation Coefficients;
- Data Reduction;
- Line Spectra;
- Magnesium;
- Solar Temperature;
- Spatial Distribution;
- Solar Physics;
- High Resolution;
- Coherence;
- Simple Model;
- Line Centre;
- Temperature Fluctuation