High-resolution infrared and microwave study of the (nu)20 and (nu)21 levels near 300 cm-1 in 1,2,4-triazine

The line profile of the CO J=5–4 transition at 576 GHz was measured precisely by a BWO-based submillimeter wave spectrometer. The foreign-gas effect on the broadening and shift of rare gases were determined together with the self-collision effects. The observed profiles exhibit clearly the Dicke narrowing effect for the cases of rare gas mixtures, and the Galatry function was used as the lineshape function in the analysis.