Lower and central panel: inner and outer radius of the emitting region. Top panel: FWHM of the line. See Sect. 3 for the description of color coding and error bars. LEFT figure: [O i] at 63 μm. The oxygen line-emitting region is generally pushed further as L_X increases, this is also reflected by the FWHM, which on average slightly decreases with L_X. Right panel: [C ii] at 157.7 μm. Ionized carbon traces the outer disk, its emitting region extends inward as L_FUV increases. X-rays do not impact considerably R_IN, R_OUT or the FHWM of the line.