title: Tricarbon monoxide in TMC-1.
abstract: We report the measurement of three new lines of C3O in TMC-1.  The observed peak antenna temperatures, appropriately corrected for atmospheric and telescope losses, are found to be consistent with a large velocity gradient radiative transfer model whose parameters span the range of standard values for this cloud.  The derived fractional abundance for C3O is 1.4 x 10(-10), comparable with the results predicted from a model calculation based on a gas-phase ion-molecule reaction scheme.  The results of negative searches for C3O in six other sources are not inconsistent with expected conditions in these clouds.
authors.affiliation: Chemistry Department, Monash University.
authors.forename: R D
authors.initials: RD
authors.lastname: Brown
authors.forename: P D
authors.initials: PD
authors.lastname: Godfrey
authors.forename: D M
authors.initials: DM
authors.lastname: Cragg
authors.forename: E H
authors.initials: EH
authors.lastname: Rice
authors.forename: W M
authors.initials: WM
authors.lastname: Irvine
authors.forename: P
authors.initials: P
authors.lastname: Friberg
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Ohishi
authors.forename: N
authors.initials: N
authors.lastname: Kaifu
authors.forename: M
authors.initials: M
authors.lastname: Morimoto
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D002248:Carbon Monoxide / Q000032:analysis* / Q000737:chemistry; D005118:Extraterrestrial Environment; D008956:Models, Chemical; D013696:Temperature
chemical_list: D002248:Carbon Monoxide