LOWTEAM · Low temperature experiments for astrochemical models

The physical conditions in the interstellar medium (ISM) are very different from those on Earth. These regions are characterized by low temperatures (~10 K) and densities (~100000 cm-3). Over the years, experimental chemists have developed new techniques to measure the reactivity of chemical species in these environments under conditions pertinent to the ISM. Only recently have techniques like the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme) demonstrated that many reactions between neutral species in the gas phase are rapid at low temperature and even display rate coefficients that increase as the temperature decreases. Most neutral-neutral reactions used in astrochemical models have large uncertainties associated with their rate coefficients due to the lack of direct measurement at low temperature. Thus, the chemistry in these models is driven largely by unquantified reactions. To make useful comparisons between observations and models, it is crucial to increase the number of laboratory measurements to reduce the model uncertainties. In this proposal we intend to focus on the reactions of nitrogen atoms at low temperatures. Indeed, although the formation and destruction of nitrogen bearing molecules are used to probe the chemical processes occurring during the pre-stellar phase, reactions of nitrogen atoms have never been studied at temperatures pertinent to the ISM. We intend to address this issue using a novel modification of the usual CRESU technique.