Second order structure function. This plot shows the second order structure function of column density (dashed purple) and velocity (blue) computed from the respective average quantity along the Maggie filament. A 2D plane fit to the velocity field has been subtracted prior to computing the velocity structure function. The vertical blue dotted line indicates the characteristic spatial scale of the velocity. The black dotted line is a power-law fit to the velocity structure function. The gray shaded area indicates the range of scales below three beams for which the recovered structure function is unreliable.