2D-spectroscopy of the Evershed flow in sunspots

The radial variation of the Evershed ow in two small sunspots (NOAA 8737 an d NOAA 9145) is studied by means of two-dimensional spectrograms of high sp atial resolution. We find a systematic decrease of the flow velocity with p hotospheric height and a shift of the velocity maximum towards larger penum bral radii in higher layers but no clear correlation between ow velocity an d continuum intensity. At the outer penumbral boundaries the Evershed flow ceases abruptly and even downward directed flow velocities in the deepest p robed photospheric layers were found. Furthermore, granules adjacent to the penumbral boundary show a systematic redshift of their spot-side parts whi ch is attributed to fast, eventually supersonic, downflows between them and the penumbral boundary.