THE C(3P) + NH3REACTION IN INTERSTELLAR CHEMISTRY. II. LOW TEMPERATURE RATE CONSTANTS AND MODELING OF NH, NH2, AND NH3ABUNDANCES IN DENSE INTERSTELLAR CLOUDS

Kevin M. Hickson, Jean-Christophe Loison, Jérémy Bourgalais, Michael Capron, Sébastien D. Le Picard, Fabien Goulay, Valentine Wakelam
2015 Astrophysical Journal  
A continuous supersonic flow reactor has been used to measure rate constants for the C + NH3 reaction over the temperature range 50 to 296 K. C atoms were created by the pulsed laser photolysis of CBr4. The kinetics of the title reaction were followed directly by vacuum ultra-violet laser induced fluorescence (VUV LIF) of C loss and through H formation. The experiments show unambiguously that the reaction is rapid at 296 K, becoming faster at lower temperatures, reaching a value of 1.8 10-10
more » ... molecule-1 s-1 at 50 K. As this reaction is not currently included in astrochemical networks, its influence on interstellar nitrogen hydride abundances is tested through a dense cloud model including gas-grain interactions. In particular, the effect of the ortho-to-para ratio of H2 which plays a crucial role in interstellar NH3 synthesis is examined.
doi:10.1088/0004-637x/812/2/107 fatcat:l75aww42mre55lpz7jbinonzva