A String of Radio Emission Associated with IRAS 16562-3959: A Collimated Jet Emanating from a Luminous Massive YSO

Abstract

We report the discovery made using the Australia Telescope Compact Array of a remarkable string of radio emission towards IRAS 16562-3959, a luminous infrared source with a bolometric luminosity of $7.0\times 10^4$ \Lsun. The radio emission arises from a compact, bright central component, two inner lobes, which are separated by about 7\arcsec\ and symmetrically offset from the central source, and two outer lobes which are separated by about 45\arcsec. The emission from the central object has a spectral index between 1.4 and 8.6 GHz of $0.85\pm 0.15$, consistent with free-free emission from a thermal jet. The radio emission from the lobes have spectral indices in the range characteristic of thermal emission. We suggest that the emission from the lobes arises in shocks resulting from the interaction of a collimated wind with the surrounding medium. The radio string is located within a massive dense molecular core, and is associated with extended green emission (Spitzer 3-color), Herbig-Haro type emission (2MASS K${}_s$-band) and OH maser sites -- all phenomena readily observed towards sites of massive star formation. We conclude that the massive core hosts a high-mass star in an early stage of evolution in which it is undergoing the ejection of a powerful collimated stellar wind, showing that jets found in the formation of low-mass stars are also produced in high-mass stars.

Accepted for publication in ApJ

References in corpus (5)

• The RMS Survey: Radio observations of candidate massive YSOs in the southern hemisphere
• The RMS Survey: Mid-Infrared Observations of Candidate Massive YSOs in the Southern Hemisphere
• The RMS Survey: ${}^{13}$CO observations of candidate massive YSOs in the northern Galactic plane
• The Collimated Jet Source in IRAS 16547-4247: Time Variation, Possible Precession, and Upper Limits to the Proper Motions Along the Jet Axis
• Kinematics of a hot massive accretion disk candidate

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• Weak and Compact Radio Emission in Early High-Mass Star Forming Regions: I. VLA Observations
• Search for ionized jets towards high-mass young stellar objects
• A search for non-thermal radio emission from jets of massive young stellar objects
• The SOFIA Massive (SOMA) Star Formation Survey. II. High Luminosity Protostars
• The Intermediate-mass Young Stellar Object 08576nr292: Discovery of a disk-jet system
• Initial phases of high-mass star formation: A multiwavelength study towards the extended green object G12.42+0.50
• Momentum-driven outflow emission from an O-type YSO: Comparing the radio jet with the molecular outflow
• Weak and Compact Radio Emission in Early Massive Star Formation Regions: An Ionized Jet Toward G11.11-0.12P1
• G345.45+1.50: An expanding ring-like structure with massive star formation
• Massive young stellar object W42-MME: The discovery of an infrared jet using VLT/NACO near-infrared images