Spectroscopy of small scale magnetic structures in the solar photosphere
If the sun is imaged in the G-band (a spectral range at 430nm that is dominated by electronic transitions of the CH-molecule) at a sufficiently high resolution, the presence of the so-called G-band bright points is revealed. They are interpreted as small-scale magnetic field concentrations that are embedded in the convective flow field of the solar photosphere. As manifestations of small scale magnetic fields, bright points become important for the understanding of the coronal heating process and the variability of the solar irradiance. Hitherto all observations of this fine structure in the G-band have been obtained with broadband interference filters that integrate the spectral intensity over a variety of absorption lines. In this thesis the physical structure of the G-band bright points and the properties of the G-band itself are investigated. The required spectral data at high spatial resolution is in part obtained with the help of a low order adaptive optic system. A comparison with synthesized spectra of different model atmospheres is done as well.
sun, solar photosphere, magnetic field, spectroscopy
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