Line-shape models testing on six acetylene transitions in the ν1+ν3 band broadened by N2

•This is a study of 6 nitrogen-broadened acetylene transitions using different line shape models.•We obtained line-shape parameters which are needed to describe an observed spectrum.•In the Dicke narrowing regime, the Rautian-Galatry profile gave best results.•Speed dependent Voigt could reproduce residuals with good accuracy for pressures in the 5-250 Torr.•We examined the impact of the shape of the molecular potential on spectra and obtained best value for the parameter q.

We present a line-shape study of six absorption lines P(21), P(16), P(19), R(16), R(19) and R(21) in the ν1+ν3 band of the acetylene perturbed by nitrogen. The spectra were recorded using a 3-channel diode laser spectrometer. For each transition studied, the N2-broadening, N2-narrowing, N2-pressure induced line shift and N2-line mixing coefficients were retrieved using several line-shape models. Moreover, we compare the N2-narrowing parameter to the dynamical friction parameter. The spectra were recorded over a pressure range from 5 to 250 Torr, and were analyzed using the Voigt, Rautian, Correlated Rautian, Galatry, Rautian-Galatry, Speed Dependent Voigt, Speed Dependent Rautian and Correlated Speed Dependent Rautian line-shape models. Furthermore, we have studied the influence of the type of interaction potential in our analysis for line-shape models that take into account speed dependent effects.