High resolution 2D-spectroscopy of granular dynamics

Spectroscopic data with high spatial resolution are used to study the granular dynamics of the Sun. The observations were obtained with the "Gottingen" two-dimensional (2D) Fabry-Perot interferometer in the Vacuum Tower Telescope at the Observatorio del Teide/Tenerife. Time sequences of spectral scans across the nonmagnetic Fe I 5576 Angstrom line were taken from disc center. The 2D spectroscopic images were reconstructed with speckle methods, from which a spatial resolution of 0 " .4-0 " .5 was achieved. A Flower and coherence analysis of intensity and velocity maps from different photospheric heights has been carried out. The coherence between intensity and velocity fluctuations stays high for structural scales >0 " .5, which underlines the high spatial resolution of the data. Furthermore, the vertical flow field and it; time evolution within exploding granules have been analyzed. We find fast downflows in the dark centers of exploding granules with velocities up to 1.2 km s(-1). Additionally, we estimated the flow velocities of so-called "dark dots". We discuss indications that these structures represent a new type of downflow within the centers of bright granules.