Correlations between diagnostic ratios for the broad and BLUE components (left lower matrix), and between physical parameters (right upper matrix). The pink dots are the outlier sources described in Sect. 4.2 and were not considered in the statistical analysis. Additionally, for each panel we excluded, if necessary, the objects with the highest dispersion from the main relation (black dots). The blue and green dots are the values considered for each relation, the solid lines show the linear fit, the shaded areas represent the confidence interval of the lineal regression. For each relation the Spearman correlation coefficient (r) is shown in the right top corner.