Two-dimensional spectroscopy and polarimetry of the sun

Two-dimensional spectroscopic and polarimetric measurements shall be performed with the "Göttingen" Fabry-Pérot-Interferometer which is installed at the Vacuum-Tower-Telescope in Tenerife, Canary Islands. The resulting data shall be reconstructed with speckle-interferometric methods. Observation targets shall be: (i) quiet granulation, (ii) small-scale magnetic elements, and (iii) sunspot penumbrae. (i) The center-to-limb variation of granular motions shall be analyzed. From these observations information about the horizontal granular flows and about the granular structure in the upper photosphere shall be obtained. (ii) Time series of 2D-spectra of active regions (abnormal granulation, facular regions, etc.) shall be obtained. The morphology and the temporal variation of flow velocities and magnetic field strengths within the magnetic elements shall be analyzed. (iii) The fine structure of the magnetic field configuration and the flow fields (Evershed flow) of sunspot penumbrae shall be studied. The effects of the magnetic fields and the Evershed flow on the nearby granulation shall be analyzed. A physical interpretation of the 2D-spectra shall be performed by inverting the measured Stokes profiles. For this purpose a program code ("SIR") developed at the Instituto de Astrofsica de Canarias shall be used.