Abstract: We investigate three sets of spectra with high spatial and spectral resolution. Each set consists of four spectra taken simultaneously with the Vacuum Tower Telescope at Izana, Tenerife. The main spectral characteristics (continuum intensity I_c_; full width at half maximum FWHM; residual intensity I_o_) were computed for 5 magnetic and non-magnetic Fe I lines (5434.543 A, 5576.099 A, 6301.497 A, 6302.499 A, 6494.994 A). Our results allow a diagnosis of the solar atmosphere in the vertical (two main levels of line formation) and horizontal directions (71 arcseconds). The spectra cover both interior parts of supergranular cells (purely quiet regions, PQR) and cell boundaries (moderate active regions, MAR). The main results are: (1) We find a different continuum intensity distribution for PQRs and MARs, which reflects the existence of different patterns in these regions. The difference is also evident in the rms residual intensity fluctuation. (2) A significant minimum of the residual intensity fluctuations ({delta}I_o_/I_c_)_rms_ occurs at a height of about 300km. (3) At all heights of the PQRs the line widths FWHM in the intergranular lanes are larger than the mean line width; those in the granules are smaller. This variation of the FWHM is influenced by a magnetic effect near the centres of the intergranular lanes (reduced FWHM), and by the effect of convection in granules (enhanced FWHM). (4) The correlation reverses its sign at a height of about 250km. The anticorrelation in the range 300-500km indicates a non-convective structure, different from the photospheric granular pattern found earlier.

Keywords: sun: photosphere - sun: granulation - line: profiles


Last update: July 23, 1996, Hubertus Wöhl, <hw@kis.uni-freiburg.de>