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Title: IRAS 16547–4247: A NEW CANDIDATE OF A PROTOCLUSTER UNVEILED WITH ALMA

We present the results of continuum and {sup 12}CO(3-2) and CH{sub 3}OH(7-6) line observations of IRAS 16547–4247 made with the Atacama Large Millimeter/submillimeter Array (ALMA) at an angular resolution of ∼0.''5. The {sup 12}CO(3-2) emission shows two high-velocity outflows whose driving sources are located within the dust continuum peak. The alignment of these outflows does not coincide with that of the wide-angle, large-scale, bipolar outflow detected with the Atacama Pathfinder Experiment in previous studies. The CH{sub 3}OH(7-6) line emission traces an hourglass structure associated with the cavity walls created by the outflow lobes. Taking into account our results together with the position of the H{sub 2}O and class I CH{sub 3}OH maser clusters, we discuss two possible scenarios that can explain the hourglass structure observed in IRAS 16547–4247: (1) precession of a biconical jet, (2) multiple, or at least two, driving sources powering intersecting outflows. Combining the available evidence, namely, the presence of two cross-aligned bipolar outflows and two different H{sub 2}O maser groups, we suggest that IRAS 16547–4247 represents an early formation phase of a protocluster.
Authors:
 [1] ; ; ;  [2] ;  [3] ;  [4]
  1. College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito 310-8512 (Japan)
  2. National Astronomical Observatory of Japan 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  3. Academia Sinica Institute of Astronomy and Astrophysics, PO Box 23-141, Taipei 10617, Taiwan (China)
  4. Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago (Chile)
Publication Date:
OSTI Identifier:
22364652
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 798; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALIGNMENT; CARBON 12; CARBON MONOXIDE; COSMIC DUST; EMISSION; EMISSION SPECTRA; JETS; MASERS; METHANOL; MOLECULES; PRECESSION; PROTOSTARS; STAR CLUSTERS; STARS; VELOCITY; WATER