2006/09/11 by Keping Qiu, Qizhou Zhang, H. Beuther +2
Chemistry · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Galaxy #Molecular Spectroscopy and Structure #Outflow #Physics #Plateau de Bure Interferometer #Protostar #Redshift #Star formation #Stars #Stellar, planetary, and galactic studies #Velocity gradient #astro-ph
paper · pdf · doi:10.1086/509069
published as Astrophys.J.654:361-372,2006 · Accepter for publication in The Astrophysical Journal
arxiv created 2006/09/11 · openalex publication_date 2006/12/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present high angular resolution observations toward two massive star-forming regions, IRAS 18264-1152 and IRAS 23151+5912, with the Plateau de Bure Interferometer (PdBI) in the SiO( J = 2-1) and H 13 CO + ( J = 1-0) lines and at 1.3 and 3.4 mm continuum, and with the Very Large Array (VLA) in the NH 3 ( J , K ) = (1,1), (2, 2) lines. The NH 3 (1, 1) and (2, 2) emission is detected toward IRAS 18264-1152 only. For IRAS 18264-1152, the SiO observations reveal at least two quasi-perpendicular outflows with high collimation factors, and the most dominant feature is a redshifted jetlike outflow with very high velocities up to about Δ v = 60 km s -1 with respect to the systemic velocity. The very high velocity component (Δ v = 22-60 km s -1 ) of this outflow is spatially offset from its high-velocity (Δ v = 3-21 km s -1 ) component. The SiO line profiles and position-velocity characteristics of these two components suggest that this outflow could be driven by an underlying precessing jet. For IRAS 23151+5912, the bipolar but mainly blueshifted SiO outflow coincides with the inner parts of the single-dish CO outflow. In particular, the quasi-parabolic shape of the blueshifted outflow coincides with the near-infrared nebulosity and is consistent with entrainment of the gas by an underlying wide-angle wind. The analysis of the molecular outflow data of the two luminous sources further supports high-mass stars forming via a disk-mediated accretion process similar to that in low-mass stars.