Observation of the line intensity and Doppler shift of Si IV 1394 Å in the quiet Sun. The data were taken with IRIS with a field of view of 104″ × 174″ centered around solar (X,Y) = ( − 120″, −48″), i.e., close to disk center. The intensity map is displayed on a logarithmic scale. Gray regions in the Doppler map mark areas where the signal is too low to perform a reliable Gaussian fit (below ca. 15% of the mean intensity or 80 DN/line for this data set). See Sect. 2 for more details.