The Case of the Q(5) Raman Line of Carbon Monoxide and its Fitted q-Gaussian Function

In an article by Thibault et al., 2002, we can find measurements of Raman linewidths in the Q branch of carbon monoxide, for mixtures with Argon at different temperatures. A plot is available for the Q(5) line with a fitted Voigt function. Here we show that a q-Gaussian Tsallis function can be used for fitting this line too. We will note that the fitted q-Gaussian has the wings which are not Lorentzian. At the same time, the wings are not Gaussian. Besides the use of q-Gaussians, a discussion will be proposed about the time correlation functions related to different line shapes (q-Gaussian, Egelstaff-Schofield, Kubo, BWF, Voigt, speed-dependent Voigt, Galatry, Rautian, HTP). Some of these line shapes have been proposed for the high-resolution spectroscopy of gases; however, their knowledge can be relevant also for the condensed matter spectroscopy.