Ro-vibrational excitation of CS by He

F. Lique, A. Spielfiedel
2006 Astronomy and Astrophysics  
Context. Over the next few years, ALMA and Herschel missions will perform high spatial and spectral resolution studies at infrared and sub-millimeter wavelengths. Modeling of the spectra will require accurate radiative and collisional rates for species of astrophysical interest. Aims. The present paper focuses on the calculation of ro-vibrational excitation rate coefficients of CS by He, useful for studies of high-temperature interstellar environments. Methods. A new accurate three dimensional
more » ... 3D) potential energy surface for the CS-He system, which explicitly takes into account the r-dependence of the CS vibration, was calculated. The dynamic calculations were performed using the VCC-IOS approximation. Results. Cross sections among the 38 first rotational levels of v = 0, v = 1 and v = 2 are calculated for total energies up to 10 000 cm −1 . Rate coefficients between the ro-vibrational levels are calculated for temperatures from 300 K to 1500 K.
doi:10.1051/0004-6361:20066422 fatcat:stjwqrgsw5hj5cvrg7p26bqlsu