Oscillator strengths for transitions to Rydberg levels in CO, CO and CO between 967 and 972 Å*
LERMA, UMR 8112 du CNRS, Observatoire de Paris, 92195 Meudon Cedex, France e-mail: email@example.com
2 LERMA/LAMAp, UMR 8112 du CNRS, Université de Cergy-Pontoise, 95031 Cergy-Pontoise, France
3 Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606, USA
Accepted: 11 May 2004
Absorption oscillator strengths have been determined from high-resolution spectra in the 967–972 Å region of three CO isotopomers for transitions to the Rydberg levels 4pπ(0), 3dπ(1) and 4pσ(0), as well as to the mixed E(6) level recently characterized by Eidelsberg et al. ([CITE]). Synchrotron radiation from the Super-ACO electron storage ring at Orsay (LURE) was used as a light source. Oscillator strengths were extracted from the recorded spectra by least-squares fitting of the experimental profiles with synthetic spectra taking into account the homogeneous and heterogeneous interactions of the four levels. Column densities were derived from fits to the 3pπ(0) absorption band whose oscillator strength is well established. These are the first reported measurements for 13C18O. For 12C16O, our results are consistent with the larger values obtained in the most recent laboratory and astronomical studies.
Key words: ISM: molecules / methods: laboratory / molecular data / ultraviolet: ISM
© ESO, 2004