title: The IRS 1 circumstellar disk, and the origin of the jet and CO outflow in B5.
abstract: We report the discovery of the inner edge of the high velocity CO outflow associated with the bipolar jet originating from IRS 1 in Barnard 5 and the first ever resolution of its circumstellar disk in the 2.6 mm dust continuum and C18O. From high spatial resolution observations made with the Owens Valley Millimeter Array we are able to locate the origin of the outflow to within approximately 500 AU on either side of IRS 1 and apparently at the edge of, or possibly within, its circumstellar disk. The orientation of the continuum disk is perpendicular to the highly collimated jet outflow recently seen in optical emission at much farther distances. The disk has been detected in C18O giving a disk mass approximately 0.16 M (solar). Our HCO+ and HCN maps indicate significant chemical differentiation in the circumstellar region on small scales with HCO+ tracing an extended disk of material. The 12CO interferometer maps of the outflow show two conelike features originating at IRS 1, the blue one fanning open to the northeast and the red one to the southwest. The vertices of the cones are on either side of the circumstellar disk and have a projected opening angle of about 90 degrees. The intrinsic opening angle is in the range of 60 degrees-90 degrees which leads to significant interaction between outflow and infall.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109, USA. langer@langer.jpl.nasa.gov
authors.forename: W D
authors.initials: WD
authors.lastname: Langer
authors.forename: T
authors.initials: T
authors.lastname: Velusamy
authors.forename: T
authors.initials: T
authors.lastname: Xie
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D002247:Carbon Isotopes; D002248:Carbon Monoxide / Q000032:analysis* / Q000737:chemistry; D019443:Cosmic Dust / Q000032:analysis*; D005118:Extraterrestrial Environment; D005740:Gases / Q000032:analysis; D006838:Hydrocarbons / Q000032:analysis; D006856:Hydrogen Cyanide / Q000032:analysis; D016011:Normal Distribution; D018540:Uranus
chemical_list: D002247:Carbon Isotopes; D019443:Cosmic Dust; D005740:Gases; D006838:Hydrocarbons; D006856:Hydrogen Cyanide; D002248:Carbon Monoxide