MARVEL Analysis of the Measured High-resolution Spectra of CO Isotopologues

Carbon monoxide is thought to be the second most abundant molecule in the Universe. This makes observation of both its parent isotopologue ( 12 C 16 O) and its stable isotopologues, 13 C 16 O, 12 C 18 O, 12 C 17 O, 13 C 18 O, and 13 C 17 O, important in variety of objects. Here the Measured Active Rotational-Vibrational Energy Levels algorithm is used to determine precise rotational–vibrational energy levels for the five minor isotopologues of carbon monoxide in their electronic ground state. A review of 27 literature sources yields 3716, 1454, 89, 728, and 57 validated transitions for 13 C 16 O, 12 C 18 O, 12 C 17 O, 13 C 18 O, and 13 C 17 O, respectively, giving 863, 499, 33, 345, and 45 empirically determined, rotation–vibration energy levels, respectively.