SMA Observations of the Hot Molecular Core IRAS 18566+0408

Journal Article · Sun Oct 01 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA88C6· OSTI ID:22875753

Silva, Andrea; Zhang, Qizhou; Sridharan, T. K. ^[1]; Sanhueza, Patricio; Lu, Xing ^[2]; Beltran, Maria T.; Cesaroni, Riccardo ^[3]; Fallscheer, Cassandra ^[4]; Beuther, Henrik ^[5]

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1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
2. National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
3. INAF—Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 (Italy)
4. Central Washington University, 400 E University Way, Ellensburg, WA 98926 (United States)
5. Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

We present Submillimeter Array (SMA) observations toward the high-mass star-forming region IRAS 18566+0408. Observations at the 1.3 mm continuum and in several molecular line transitions were performed in the compact (2.″4 angular resolution) and very-extended (∼0.″4 angular resolution) configurations. The continuum emission from the compact configuration shows a dust core of 150 M {sub ⊙}, while the very-extended configuration reveals a dense (2.6 × 10{sup 7} cm{sup −3}) and compact (∼4000 au) condensation of 8 M {sub ⊙}. We detect 31 molecular transitions from 14 species including CO isotopologues, SO, CH{sub 3}OH, OCS, and CH{sub 3}CN. Using the different k-ladders of the CH{sub 3}CN line, we derive a rotational temperature at the location of the continuum peak of 240 K. The {sup 12}CO(2−1), {sup 13}CO(2−1), and SO(6{sub 5}--5{sub 4}) lines reveal a molecular outflow at PA ∼ 135° centered at the continuum peak. The extended {sup 12}CO(2−1) emission has been recovered with the IRAM 30 m telescope observations. Using the combined data set, we derive an outflow mass of 16.8 M {sub ⊙}. The chemically rich spectrum and the high rotational temperature confirm that IRAS 18566+0408 is harboring a hot molecular core. We find no clear velocity gradient that could suggest the presence of a rotational disk-like structure, even at the high-resolution observations obtained with the very-extended configuration.

• OSTI ID: 22875753
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 847; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CARBON MONOXIDE
COSMIC DUST
EMISSION
MASS
METHANOL
SPECTRA
STAR EVOLUTION
STARS
TELESCOPES