High-resolution emission spectrum of OH in an oxyacetylene flame from 3.7 to 0.9 μm

Abstract

The vibration-rotation OH spectrum emitted by an acetylene oxygen flame has been measured between 2700 and 11 000 cm −1 with a high-resolution Fourier Spectrometer. The main interferences in the spectra are due to water vapor absorption and emission which are mixed with OH in the source. Nevertheless, line positions to high J values (more than 20 for some P branches) of the 1-0 and 2-1 bands of the Δ v = 1 sequence, 2-0, 3-1, 4-2, and 5-3 of Δ v = 2 and 3-0, 4-1, and 5-2 of the Δ v = 3 sequence are reported. Bands of the Δ v = 3 sequence are reported here for the first time. Ground-state molecular constants of OH were derived from a least-squares fit of the data, weighted according to their estimated uncertainties. Uncertainties in the new set of molecular constants are considerably improved relative to the previously available constants. Predicted positions of some unobserved bands of OH have been calculated from these new constants for the purpose of aiding stellar and atmospheric studies.