On the departure from translational equilibrium for interstellar molecular hydrogen

Abstract

view Abstract Citations (1) References (5) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the departure from translational equilibrium for interstellar molecular hydrogen. Shizgal, B. Abstract Nonequilibrium effects in interstellar hydrogen are examined by using methods that yield essentially exact solutions to the Boltzmann equation valid for all values of the reduced threshold energy. The method adopted for solving the Boltzmann equation is briefly outlined, the exact results are compared with a correction to the equilibrium rate calculated by Gould and Levy (1976), and the reduced threshold energy is determined for which reliable estimates of that correction can be obtained. The nonequilibrium effects are then evaluated for all values of the reduced threshold energy, especially that of approximately unity. It is shown that the nonequilibrium effects may not be as large as previously expected and should not significantly alter equilibrium estimates of the inelastic transition rate. Publication: The Astrophysical Journal Pub Date: October 1977 DOI: 10.1086/155555 Bibcode: 1977ApJ...217...78S Keywords: Boltzmann Transport Equation; Hydrogen; Inelastic Collisions; Interstellar Chemistry; Molecular Rotation; Nonequilibrium Conditions; Activation Energy; Collision Parameters; Maxwell-Boltzmann Density Function; Temperature Effects; Translational Motion; Velocity Distribution; Astrophysics full text sources ADS |