An H2CO 6cm Maser Pinpointing a Possible Circumstellar Torus in IRAS18566+0408

Abstract

We report observations of 6cm, 3.6cm, 1.3cm, and 7mm radio continuum, conducted with the Very Large Array towards IRAS18566+0408, one of the few sources known to harbor H2CO 6cm maser emission. Our observations reveal that the emission is dominated by an ionized jet at cm wavelengths. Spitzer/IRAC images from GLIMPSE support this interpretation, given the presence of 4.5um excess emission at approximately the same orientation as the cm continuum. The 7mm emission is dominated by thermal dust from a flattened structure almost perpendicular to the ionized jet, thus, the 7mm emission appears to trace a torus associated with a young massive stellar object. The H2CO 6cm maser is coincident with the center of the torus-like structure. Our observations rule out radiative pumping via radio continuum as the excitation mechanism for the H2CO 6cm maser in IRAS18566+0408.

20 pages, 4 figures, ApJ (in press)

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Cited by in corpus (6)

• A Catalog of Extended Green Objects (EGOs) in the GLIMPSE Survey: A new sample of massive young stellar object outflow candidates
• A Search for H2CO 6cm Emission toward Young Stellar Objects III: VLA Observations
• Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers
• SMA Observations of the Hot Molecular Core IRAS 18566+0408
• High Resolution Observations of the Massive Protostar in IRAS18566+0408
• Broadband VLA Spectral Line Survey of a Sample of Ionized Jet Candidates