Correlation analysis of several physical properties in comparison to the fitted HBA and L-band radio scale heights (z_{0, HBA}, z_{0, L-band}) and the ratio of HBA and the L band (r). The main diagonal displays the distribution of z0 and r as well as the other analysed quantities (SFR, SFR surface density, and equipartition magnetic field strength) as histograms and kernel density estimates. Bottom: bivariate scatter plots for pairs of the analysed quantities with interpolation line. Top: colour coded (blue: negative, red: positive) Spearman rank correlation coefficients.