title: Hydrogenation of interstellar molecules: a survey for methylenimine (CH2NH).
abstract: Methylenimine (CH2NH) has been convincingly detected for the first time outside the Galactic center as part of a study of the hydrogenation of interstellar molecules. We have observed transitions from energy levels up to about 100 K above the ground state in the giant molecular clouds W51, Orion KL and G34.3 + 0.15. In addition, CH2NH was found at the " radical-ion peak" on the quiescent ridge of material in the Orion molecular cloud. The abundance ratio CH2NH/HCN at the radical-ion peak agrees with the predictions of recent gas-phase chemical models. This ratio is an order of magnitude higher in the warmer cloud cores, suggesting additional production pathways for CH2NH, probably on interstellar grains.
authors.affiliation: Five College Radio Astronomy Observatory, University of Massachusetts, Amherst 01003, USA. dickens@fcrao1.phast.umass.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Dickens
authors.forename: W M
authors.initials: WM
authors.lastname: Irvine
authors.forename: C H
authors.initials: CH
authors.lastname: DeVries
authors.forename: M
authors.initials: M
authors.lastname: Ohishi
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D019443:Cosmic Dust; D005118:Extraterrestrial Environment; D005740:Gases / Q000032:analysis*; D006865:Hydrogenation; D007097:Imines / Q000032:analysis / Q000737:chemistry*
chemical_list: D019443:Cosmic Dust; D005740:Gases; D007097:Imines; C024664:methyleneimine