FOURIER TRANSFORM SPECTROSCOPY OF THE HERZBERG I BANDS OF $O_{2}$

1. G Herzberg, Can. J. Phys. 30, 185 (1952). 2. P.M. Borrell, P. Borrell, and D.A. Ramsay, Can. J. Phys. 64, 721 (1986)Author Institution: Harvard- Smithsonian Center for Astrophysics; Blackett Laboratory, Imperial CollegeFourier transform (FT) spectroscopic measurements of the absorption bands of the Herzberg I system ($A^{3} \Sigma^{+}_{u}-X^{3} \Sigma_{g}^{-}$) of $O_{2}$ have been made in the wavelength region 240--270 nm. The FT spectrometer at Imperial College, London is combined with a white cell, that provides a pathlength of 82-m with 16 round trips. The (4,0) through (11,0) absorption bands have been observed and their rotational line positions are determined with an accuracy of $\pm 0.005 cm^{-1}$. A weak perturbation is noticed in the $F_{3}$ component of the (7,0) band by interaction with the $c(12)$ level. Perturbations are also seen in the (11,0) band as have been noticed previously by $Herzberg^{1}$ and Borrell $et at^{2}$. Molecular constants of the $A-X$ system will be presented. This work is supported by NSF Division of Atmospheric Sciences grants ATM-91-16552 to Harvard College Observatory