Estimated Stokes I at 144 MHz from a grid of prestellar-core models – see one example in Fig. 8 – as a function of the magnetic support (H₀) and the effective sound speed in the medium (c_s,eff). The corresponding mass-to-flux ratio (λ_r) is also displayed on the top of each panel. In the left and central panels, two different emissivity models are considered (Padovani et al. 2018; Bracco et al. 2024). In the right panels, for each pair of parameters (c_s,eff, H₀), we show the corresponding magnetic-field strength averaged within 0.1 pc from the center. In the two rows we integrate the models either edge-on (top) or face-on (bottom). Black hatches define the non-detection areas in the LOFAR data for Stokes I values greater than 5 μJy beam⁻¹. The dashed white lines at 2 μJy beam⁻¹ indicate the sensitivity in Perseus of SKA-Low for ~9 hours of observations in stage AA* and ~4 hours in stage AA4.