SMA Observations of the Hot Molecular Core IRAS 18566+0408

Abstract

We present Submillimeter Array (SMA) observations toward the high-mass star-forming region IRAS 18566+0408. Observations at 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 Msun, while the very-extended configuration reveals a dense (2.6 x 10^7 cm^-3) and compact (~4,000 AU) condensation of 8 Msun. We detect 31 molecular transitions from 14 species including CO isotopologues, SO, CH3OH, OCS, and CH3CN. Using the different k-ladders of the CH3CN line, we derive a rotational temperature at the location of the continuum peak of 240 K. The 12CO(2-1), 13CO(2-1), and SO(6_5-5_4) lines reveal a molecular outflow at PA ~135^o centered at the continuum peak. The extended 12CO(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 Msun. 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.

14 pages, 10 figures, Accepted for publication in ApJ

References in corpus (7)

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Cited by in corpus (7)

• ATOMS:ALMA Three-millimeter Observations of Massive Star-forming regions -- III :Catalogues of candidate hot molecular cores and Hyper/Ultra compact HII regions
• Digging into the Interior of Hot Cores with ALMA (DIHCA). I. Dissecting the High-mass Star-Forming Core G335.579-0.292 MM1
• A Detailed View of the Circumstellar Environment and Disk of the Forming O-star AFGL 4176
• A spectral survey of CH3CCH in the Hot Molecular Core G331.512-0.103
• Hot Molecular Core Candidates in the Galactic Center 50 km/s Molecular Cloud
• Surveys of clumps, cores, and condensations in Cygnus-X: Searching for Keplerian disks on the scale of 500 au
• First detection of methyl formate in the hot molecular core IRAS 18566+0408