2007A&A...472.1037V -
Astronomy and Astrophysics, volume 472, 1037-1040 (2007/9-4)
Rotational excitation of SiS molecules by collisions with He atoms.
VINCENT L.F.M., SPIELFIEDEL A. and LIQUE F.
Abstract (from CDS):
Observations of molecular emission at millimeter and infrared wavelengths, supplemented by careful and detailed modeling, are powerful tools for investigating the physical and chemical conditions of astrophysical objects. Modeling of molecular emission requires excitation calculations using radiative as well as collisional rates with the most abundant species. The present paper focuses on the calculation of rate coefficients among the first rotational levels of the SiS molecule in its ground vibrational state in collision with He. A new accurate two dimensional potential energy surface system was calculated for the SiS-He system using highly correlated ab initio calculations. Dynamical calculations of pure rotational (de)excitation of SiS by collisions with He were performed for the first rotational levels using the near exact close-coupling approach. Collisional cross sections among the 26 first rotational levels of SiS were calculated for kinetic energies up to 1500/cm. Rate coefficients between the rotational levels were calculated for temperatures ranging from 5 to 200K. A propensity rule that favors even Δj transitions is found and is explained by the small asymmetry of the SiS-He potential energy surface.
Abstract Copyright:
∼
Journal keyword(s):
ISM: molecules - molecular data - molecular processes
Simbad objects:
1
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2007A&A...472.1037V and select 'bookmark this link' or equivalent in the popup menu