Kinetic Temperature Rate Coefficients for Dissociative Recombination of CH +

Abstract The rate coefficient for dissociative recombination (DR) of CH + is needed to model clouds in the interstellar medium (ISM). Theoretical data for DR are typically obtained in the form of cross sections as a function of collision energy. However, astrochemical modelers need rate coefficients as a function of the kinetic temperature of the gas, i.e., the cross section averaged over the electron velocity distribution of the plasma. Molecules in the ISM are typically in their lowest energy states. To this end, we have calculated the kinetic temperature rate coefficients for DR of electronically, vibrationally, and rotationally cold CH + over a temperature range of 1–5000 K, using theoretical cross sections from J. Forer et al. We have also fit our results to two commonly used modeling formulae and present the corresponding fit parameters.