Relation of the effective values κ₀ and β derived by fitting a modified black-body function to the theoretical dust emission spectrum of condensed cores. The symbols represent the same external pressure p_ext/k of the medium surrounding the filaments as in Fig. 9 (diamonds for 2  ×  10⁴   K/cm³, triangles for 10⁵   K/cm³, and squares for 10⁶   K/cm³). The symbols corresponding to filaments pressurized by the mean ISM pressure are labeled with the assumed central extinction of the filament. The curves are the derived fits for β and κ₀ shown in Fig. 9.