THE IRS-1 CIRCUMSTELLAR DISK, AND THE ORIGIN OF THE JET AND CO OUTFLOW IN B5

We report the discovery of the inner edge of the high velocity CO outf low 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 m m dust continuum and (CO)-O-18. From high spatial resolution observati ons made with the Owens Valley Millimeter Array we are able to locate the origin of the outflow to within similar to 500 AU on either side o f IRS 1 and apparently at the edge of, or possibly within, its circums tellar disk. The orientation of the continuum disk is perpendicular to the highly collimated jet outflow recently seen in optical emission a t much farther distances. The disk has been detected in (CO)-O-18 givi ng a disk mass similar to 0.16 M.. Our HCO+ and HCN maps indicate sign ificant chemical differentiation in the circumstellar region on small scales with HCO+ tracing an extended disk of material. The (CO)-C-12 i nterferometer maps of the outflow show two conelike features originati ng at IRS 1, the blue one fanning open to the northeast and the red on e to the southwest. The vertices of the cones are on either side of th e circumstellar disk and have a projected opening angle of about 90 de grees. The intrinsic opening angle is in the range of 60 degrees-90 de grees which leads to significant interaction between outflow and infal l.