Density and magnetic field strength profiles as a function of radius (upper and lower panels, respectively). Left column: models of starless cores described by Eq. (8), r₀ = 14″, q = 2.5 (model A, solid blue line), r₀ = 30″, q = 2.5 (model B, solid green line), and r₀ = 75″, q = 4 (model C, solid red line). Right column: starless cores FeSt 1-457 (purple) and B68 (orange). Shaded areas in the lower panels encompass the curves obtained with Eq. (9) using κ = 0.5 and 0.7 for models A, B, C and B68 and κ = 0.68 and 0.88 for FeSt 1-457 (upper and lower boundary, respectively).