Upper panels: relationship between the 20 cm radio luminosity and the Hα luminosity corrected for dust attenuation using the Balmer decrement (left) and the 24 μm luminosity following the prescription of Calzetti et al. (2010; right). Black symbols are for galaxies with a σ [C(Hβ)] ≤ 0.1, red symbols for σ [C(Hβ)] > 0.1. Filled dots are for galaxies with a normal gas content (HI - def ≤ 0.4), empty symbols for gas-poor objects (HI - def > 0.4). The black short-dashed line in the left panel shows the bisector fit determined using the best quality sample (σ [C(Hβ)] ≤ 0.1), while the red dotted line is the best fit determined using the whole sample. The green long-dashed line gives the bisector fit in the L(20 cm) vs. L(Hα)_{24 μm} relation determined using all galaxies in the right panel. When plotted in the left panel, this fit is close to the one traced by the black dashed line. Lower panels: relationship between the distance from the L(20 cm) vs. L(Hα)_BD (left) and the L(20 cm) vs. L(Hα)_{24 μm} relations (right) and the uncertainty on the Balmer decrement estimate σ [C(Hβ)].