Argon broadening of the 13CO <f>R(0)</f> and <f>R(7)</f> transitions in the fundamental band at temperatures between 80 and 297 K: comparison between experiment and theory

We present measurements of Ar-broadening parameters for the <f>R(0)</f> and <f>R(7)</f> lines in the fundamental band of 13CO at eight temperatures from 80 to 297 K. The broadening parameters are determined by simultaneous least-squares fitting of spectra recorded using a frequency stabilized diode laser spectrometer. The comparison of the broadening parameter values for <f>R(7)</f> derived at room temperature and different pressures from different line profiles shows that an empirical line profile, which takes into account narrowing effects (Dicke narrowing and absorber speed dependence) but neglects any correlation between collisions, is able to describe the observed lines with constant values of the narrowing and broadening parameters over a 10–500 Torr pressure range. Starting from a recent ab initio potential energy surface, theoretical thermally averaged close coupling values of the Ar broadening parameter are calculated for the same temperatures. The comparison between experimental and calculated values shows an overall agreement of 1.5%. [Copyright &y& Elsevier]