Document Type


Department or Administrative Unit


Publication Date



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 (2ʺ4 angular resolution) and very-extended (~0ʺ4 angular resolution) configurations. The continuum emission from the compact configuration shows a dust core of 150 M , while the very-extended configuration reveals a dense (2.6 × 107 cm−3) and compact (~4000 au) condensation of 8 M . 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(65–54) lines reveal a molecular outflow at PA ~ 135° 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 M . 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.


The download link on this page is to a draft manuscript version of this article and may not be the final version of this article. This article was originally published in The Astrophysical Journal. The full-text article from the publisher can be found here.


The Astrophysical Journal


© 2017. The American Astronomical Society. All rights reserved.