Figure 1. Left (a): χ-function calculated by Eq. (10) with the use of the parameters A=20 and Δνwing=11 cm-1 as a function of the detuning frequency. Right (b): Lorentz profile with a half-width of 5 *10-3 cm-1 (150 MHz) (bold solid line); the same profile with the wings cut off at the ±25 cm-1 detuning and the cut-off line “brought down” to the zero level (as in the CKD model) (thin solid line); the latter profile with the added wings, which are calculated by Eq. (8) using the χ-function shown on Fig.1a is presented by the dashed line.