The high velocity outflow in NGC6334I

Abstract

We observed the high velocity outflow originating from NGC6334I in several CO transitions with the APEX telescope, with the goal of deriving the physical parameters of the gas. Using an LVG analysis, we studied line ratios between the CO(3-2), CO(4-3), and CO(7-6) data as a function of the density and of the kinetic temperature of the gas. An upper limit on the CO column density is derived by comparison with 13CO data. We constrained the temperature to be higher than 50 K and the H_2 density to values higher than n~10^4 cm^{-3} towards the peak position in the red lobe, while T>15 K and n>10^3 cm^{-3} are derived towards the peak position in the blue lobe. The physical parameters of the outflow, its mass and its energetics, have been computed using the temperatures derived from this analysis. We conclude that high kinetic temperatures are present in the outflow and traced by high excitation CO lines. Observations of high-J CO lines are thus needed to infer reliable values of the kinetic temperatures and of the other physical parameters in outflows.

APEX A&A special issue, accepted

Cited by in corpus (5)

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• ATCA 3mm observations of NGC6334I and I(N): dense cores, outflows and an UCHII region
• A survey of SiO 5-4 emission towards outflows from massive young stellar objects
• High mass star formation in the IRAS 17233-3606 region: a new nearby and bright hot core in the southern sky
• The interaction of young massive stars with their environment: A millimeter and submillimeter line study of NGC6334 FIR II