Impact of New Data for the C+H3 Reaction on Gas-Phase Synthesis of Amino Acid Precursors

The complex carbon chemistry necessary for astrobiology in the ISM depends partially on the C + H3 + reaction. Gas-phase astrochemical models use a classically calculated thermal rate coefficient for the reaction C+H3 + forming CH; additionally, those models consider the CH2 + and CH3 + channels to be closed. However, new laboratory data have shown the CH2 + channel to be open; additionally, these data suggest that the temperature dependence of the two pathways cannot be reproduced by the classical calculations. We utilize new data for the reaction of C + H3 + forming CH and CH2 + to update current astrochemical models; here, we report the reduction of uncertainty in the astrochemical database KIDA. Additionally, we investigate the formation pathways for CH2NH and CH3NH2, two precursors to the amino acid glycine that depend heavily on interstellar organic synthesis. We find that our gas-phase model more accurately reproduces observed abundances of CH2NH and CH3NH2 than do previous gas-grain models, and we report here the set of reactions that our model predicts to play a major role in forming CH2NH and CH3NH2. Subject headings: Astrobiology — Astrochemistry — ISM: molecules — ISM: individual objects (Sgr B2(N))