Radio-IR correlation (q-parameter) versus total and turbulent magnetic field strength a) and star formation surface density Σ_SFRb). The magnetic field strength-Σ_SFR relation is shown for the total, turbulent c), and the ordered magnetic field strength measured by the degree of polarization d). The lines in the upper panels are the bisector fits. The solid lines in c) and d) show the ordinary least square fit, and the dashed line the bisector fit. In panel d), the binned data points (diamonds) are fitted for Σ_SFR ≳0.01 M_⊙ yr^-1 kpc^-2 (solid line). In panels a) and c), the total magnetic field is shifted up by 0.3 units for clarity. The nucleus is not included in these analysis.