Fourier transform emission spectroscopy of Δv = 2 sequence bands of the CO molecule in the ground electronic state

High-resolution emission spectroscopy of rovibrational Δv = 2 sequence bands is carried out from a low-pressure discharge through pure CO gas. The effect of rare gases on the production of the Δv = 2 sequence bands is also studied. The v′ → (v′-2) sequence bands up to v′ = 17 are observed. Bands involving 8 ⩽ v′ ⩽ 17 in the Δv = 2 sequence are reported for the first time. The 16-14 and 17-15 bands could be observed only in the presence of xenon as a buffer gas. Accurate molecular constants (T, B, D, H) for different vibrational states of the ground electronic state of 12C16O are determined from a global fit.