The Si IV observations were performed on April 22, 1996 on a quiet solar region. The 0.3 120 arcsecond slit (oriented North-South) was positioned at disk centre, and a raster of 39 by 120 arcseconds was performed, comprising 102 separate, 60-second exposures with a raster increment of 0.38 arcseconds East. Six spectral regions were obtained (each 2 Å wide), centred on the theoretical wavelengths of the Si IV emission lines; 815.05, 818.13, 1122.49, 1128.33, 1393.76 and 1402.77 Å. Standard SUMER software was used to correct for non-uniform detector sensitivity as well as wavelength and spatial distortions on the detector. Finally, the individual exposures for each spectral region were averaged to maximize the signal-to-noise ratios.
© European Southern Observatory (ESO) 1999
Online publication: June 17, 1999