Distribution of nonthermal velocity dispersion as a function of position along each of the L1517 filaments. Blue squares represent C¹⁸O(1–0) and red triangles and N₂H⁺(1–0) values. The spatial scale for filament 3 has been shrunk by a factor of 1.5 in order to fit it into the reduced box size used for the other filaments. The mean formal error in the σ_NT/c_s determination is 0.1 for both N₂H⁺ and C¹⁸O, which is approximately the marker size.