Imaging spectroscopy of solar pores

Abstract

Time series of two-dimensional spectra and corresponding broad band images of solar pore regions have been obtained with the Gottingen Fabry-Perot Interferometer at the Vacuum Tower Telescope in Izana, Tenerife. Line bisector shifts have been used for the computation of line-of-sight velocities in the studied regions. Additionally, a local correlation tracking (LCT) algorithm has been applied to obtain horizontal flow velocities from the time series of broad band images. Resulting velocity maps show that within the pore umbrae the flows are almost completely inhibited by the magnetic fields. This also holds for umbral dots and light bridges. On the boundaries of several pore umbrae persistent downflow channels are visible. The structure and temporal evolution of these phenomena have been studied. Finally, the formation of a protopore out of magnetic bright points has been analyzed. The obtained observational results are in good agreement with numerical models and common theoretical scenarios explaining the behaviour and formation of solar pores.