Formation of the negative molecular ion MH- by radiative association of a neutral molecule M with H-

We consider the formation of negative molecular ions MH$^{-}$ through the reaction of radiative association: M+H$^{-} \quad \to $ MH$^{-}$ + ?$\omega $, where M is a diatomic or triatomic neutral molecule. We present a theoretical approach to calculate the cross-section and the rate constant for the reaction and apply the theory to study formation of molecular ions from H$^{-}$ and neutral molecules abundant in the interstellar medium (ISM): We consider H$_{2}$, CO, and H$_{2}$O as possible candidates to form negative ions. Such ions have never been observed in the ISM. Their eventual observation would serve as a proof of presence of H$^{-}$ in the ISM too. The H$^{-}$ ion cannot be detected directly by the photoabsorption spectroscopy. Supported by Triangle de la Physique contract QCCM and the National Science Foundation grant PHY-0855622