Study on the (1, 2) and (2, 3) bands in the comet-tail system of 12C16O+ by optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy

Optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy was employed to observe the absorption spectra of the (1, 2) and (2, 3) bands of the comet-tail (A² Π_i—X²Σ⁺) system of CO⁺ in the visible region. A rotational analysis was performed to obtain more precise molecular constants for the four involved vibrational levels. Moreover, accurate RKR potentials and the Franck-Condon factors are given for these four vibronic levels. This calclulation reveals that v = 0, 5, 10 vibrational levels in the A state will be perturbed by the v = 10, 14, 18 levels in the × state, respectively, and the v = 9 level might be weakly perturbed by the v = 17 level.