Comparison between the observed H¹³CO⁺ (1–0) integrated intensity as a function of the offset from the core center with the predictions of our model for different cosmic-ray ionization rates (solid, dotted and dashed lines) in L1498 (left panel) and L1517B (right panel). The solid curves correspond to the fiducial models (ζ = 3 × 10^-17 s^-1). The dashed curves (labeled ζ = f(A_v)) correspond to model predictions for a variable cosmic ionization rate as a function of A_v (see text).