2014ApJS..211....5R

We present new, accurate predictions for rotational line positions, excitation energies, and transition probabilities of the ¹²C¹³C isotopologue Swan d³Π-a³Π system 0-0, 0-1, 0-2, 1-0, 1-1, 1-2, 2-0, 2-1, and 2-2 vibrational bands. The line positions and energy levels were predicted through new analyses of published laboratory data for the ¹²C¹³C lines. Transition probabilities were derived from recent computations of transition dipole moments and related quantities. The ¹²C¹³C line data were combined with similar data for ¹²C_2, reported in a companion paper, and applied to produce synthetic spectra of carbon-rich metal-poor stars that have strong C₂Swan bands. The matches between synthesized and observed spectra were used to estimate band head positions for a few of the ¹²C¹³C vibrational bands and to verify that the new computed line data match observed spectra. The much weaker C₂lines of the bright red giant Arcturus were also synthesized in the band head regions.