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

Abstract

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
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 798; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
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

Citation Formats

Higuchi, Aya E., Saigo, Kazuya, Chibueze, James O., Sanhueza, Patricio, Takakuwa, Shigehisa, and Garay, Guido. IRAS 16547–4247: A NEW CANDIDATE OF A PROTOCLUSTER UNVEILED WITH ALMA. United States: N. p., 2015. Web. doi:10.1088/2041-8205/798/2/L33.
Higuchi, Aya E., Saigo, Kazuya, Chibueze, James O., Sanhueza, Patricio, Takakuwa, Shigehisa, & Garay, Guido. IRAS 16547–4247: A NEW CANDIDATE OF A PROTOCLUSTER UNVEILED WITH ALMA. United States. https://doi.org/10.1088/2041-8205/798/2/L33
Higuchi, Aya E., Saigo, Kazuya, Chibueze, James O., Sanhueza, Patricio, Takakuwa, Shigehisa, and Garay, Guido. 2015. "IRAS 16547–4247: A NEW CANDIDATE OF A PROTOCLUSTER UNVEILED WITH ALMA". United States. https://doi.org/10.1088/2041-8205/798/2/L33.
@article{osti_22364652,
title = {IRAS 16547–4247: A NEW CANDIDATE OF A PROTOCLUSTER UNVEILED WITH ALMA},
author = {Higuchi, Aya E. and Saigo, Kazuya and Chibueze, James O. and Sanhueza, Patricio and Takakuwa, Shigehisa and Garay, Guido},
abstractNote = {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.},
doi = {10.1088/2041-8205/798/2/L33},
url = {https://www.osti.gov/biblio/22364652}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 798,
place = {United States},
year = {Sat Jan 10 00:00:00 EST 2015},
month = {Sat Jan 10 00:00:00 EST 2015}
}