Distribution of the intensity, line width, and velocity in the LB sample (green) compared to the umbra (black) and quiet Sun (red) samples. The quiet Sun area surrounding sunspots includes some plage regions seen as a secondary population in the photosphere (panel A). Histograms of the intensity parameters are shown in panels A–H, while panels I–L, and M–P show histograms of the line widths and velocities, respectively. The line width of Mg ii k₂ shown on panel (I) marks the average width of the two Gaussians used to fit the line. All intensity parameters (panels A–H) were normalized to the corresponding integration times. Positive velocity denotes redshift.