Normalized integrated intensity profiles of the HD 1–0 R(0) line, H₂ 0–0 S(1) line, and H₂ 1–0 S(1) line across the third dissociation front DF 3 as a function of the projected distance to the star Θ¹ Ori C. The distance to the Orion Bar used to calculate the distance to the star in arcsec is d = 414 pc (Menten et al. 2007). Each point corresponds to the intensity averaged on apertures with width of 2.5″ and height of 0.4″ with an angle of 38° (to match DF3 orientation) to increase the S/N.