title: Deuterium hyperfine structure in interstellar C3HD.
abstract: The deuterium nuclear quadrupole hyperfine structure of the transition 1(10)-1(01) of the ring molecule cyclopropenylidene-d1 (C3HD) has been observed in emission from interstellar molecular clouds.  The narrowest linewidths (approximately 7 kHz) so far observed are in the cloud L1498.  The derived D coupling constants Xzz = 186.9(1.4) kHz, eta=0.063(18) agree well with correlations based on other molecules.
authors.affiliation: Herzberg Institute of Astrophysics, National Research Council of Canada, Ottawa, Ontario.
authors.forename: M B
authors.initials: MB
authors.lastname: Bell
authors.forename: J K
authors.initials: JK
authors.lastname: Watson
authors.forename: P A
authors.initials: PA
authors.lastname: Feldman
authors.forename: H E
authors.initials: HE
authors.lastname: Matthews
authors.forename: S C
authors.initials: SC
authors.lastname: Madden
authors.forename: W M
authors.initials: WM
authors.lastname: Irvine
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D003903:Deuterium / Q000032:analysis / Q000737:chemistry*; D005118:Extraterrestrial Environment; D006838:Hydrocarbons / Q000032:analysis*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D006838:Hydrocarbons; D003903:Deuterium