Pixel-by-pixel velocity cross-correlations between different lines. From top to bottom, left to right: Ca II 8498 vs. 8662 Å, Ca II K vs. Ca II 8498 Å, Ca II 8498 Å vs. Hα, Ca II 8222 Å vs. He I 5875 Å, Hα vs. He I 5875 Å, and Ca II 8498 Å vs. Hβ. The correlation coefficient (estimated as a Spearman rank correlation with value r and false alarm probability p) is shown on the right in the colour scheme, with the contours marking the high significance (p> 10^-5) areas with r = 0.6,0.7,0.8,0.9.