Shape of collision-broadened lines of carbon monoxide

•The parameters of the collisional line narrowing have been obtained.•Numerical simulation is suggested to evaluate applicability of the HTP model.•It is shown, that wind effect has dominant influence on the line shape.

We consider lineshape of the rotational spectrum of a CO molecule under the conditions of prevailing collisional broadening. Several series of experimental data obtained at relatively high (up to 1000) signal-to-noise ratio of self-broadening and broadening by noble gases have been analyzed. We used for analysis several well known models beyond the Voigt profile. It is confirmed that the use of the Hartman-Tran profile needs certain requirements in order to obtain meaningful and unambiguous results. A simple numerical simulation is suggested to evaluate the result of the model usage for any particular set of experimental data. Parameters of the collisional line narrowing were obtained. It is shown that under the experimental conditions, deviations of the shape of the observed lines from the Voigt profile are solely due to the wind effect.