Low temperature gas phase reaction rate coefficient measurements: Toward modeling of stellar winds and the interstellar medium
Abstract
Stellar winds of Asymptotic Giant Branch (AGB) stars are responsible for the production of ∼85% of the gas molecules in the interstellar medium (ISM), and yet very few of the gas phase rate coefficients under the relevant conditions (10 - 3000 K) needed to model the rate of production and loss of these molecules in stellar winds have been experimentally measured. If measured at all, the value of the rate coefficient has often only been obtained at room temperature, with extrapolation to lower and higher temperatures using the Arrhenius equation. However, non-Arrhenius behavior has been observed often in the few measured rate coefficients at low temperatures. In previous reactions studied, theoretical simulations of the formation of long-lived pre-reaction complexes and quantum mechanical tunneling through the barrier to reaction have been utilized to fit these non-Arrhenius behaviours of rate coefficients.
- Publication:
-
Laboratory Astrophysics: From Observations to Interpretation
- Pub Date:
- 2020
- DOI:
- 10.1017/S1743921319007531
- Bibcode:
- 2020IAUS..350..382W
- Keywords:
-
- methods: laboratory;
- ISM: molecules;
- molecular processes;
- kinetics