Line strengths and updated molecular constants for the C2 Swan system

New rotational line strengths for the C2 Swan system (dΠg3-aΠu3) have been calculated for vibrational bands with v′=0-10 and v″=0-9, and J values up to J=34-96, using previous observations in 33 vibrational bands. Line positions from several sources were combined with the results from recent deperturbation studies of the v′=4 and v′=6 levels, and a weighted global least squares fit was performed. The updated molecular constants are reported. The line strengths are based on a recent ab initio calculation of the transition dipole moment function. A line list has been made available, including observed and calculated line positions, Einstein A coefficients and oscillator strengths (f-values). The line list will be useful for astronomers, combustion scientists and materials scientists who utilize C2 Swan spectra. Einstein A coefficients and f-values were also calculated for the vibrational bands of the Swan system.

► Line positions from several previous studies of the C2 Swan system are combined. ► Molecular constants have been recalculated including v′=4 and v′=6 perturbations. ► Rotational line intensities are calculated as Einstein A and f-values. ► Vibrational band Einstein Av′v″ and fv′v″ values are calculated. ► We give a line list up to v′=10, v″=9 with intensities for obs. and calc. lines.