A&A 425, 981-995 (2004)
Collimated molecular jets from high-mass young stars: IRAS 18151-1208C. J. Davis1, W. P. Varricatt1, S. P. Todd2 and S. K. Ramsay Howat2
1 Joint Astronomy Centre, 660 North A'ohoku Place, University Park, Hilo, Hawaii 96720, USA
2 UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, UK
(Received 15 May 2004 / Accepted 22 June 2004)
Recent near-IR images of massive star forming regions have revealed two collimated jets in the IRAS 18151-1208 region, one of which is almost a parsec in length (Varricatt et al.). Follow-up high-spectral-resolution echelle spectroscopy and 2-dimensional "integral field" spectroscopy of the associated molecular shock features are presented here. From these data kinematic information and excitation maps are extracted, which show that the two jets are morphologically, kinematically and energetically similar to their counterparts from low mass protostars. The close association between the H 2 emission features and the high-velocity CO emission presented by Beuther et al. also suggests that the CO represents gas entrained by these two very collimated jets. From the mass and momentum of the molecular gas, and the luminosity of the H 2 features, it is clear that the flows must be powered by massive sources. To all intents and purposes, the molecular jets appear to be scaled-up versions of low-mass YSO jets. Collectively, the observations add further support to the idea that massive stars are formed through vigorous disk accretion, and that, while in their earliest stages of evolution, massive protostars drive collimated jets.
Key words: molecular data -- shock waves -- stars: formation -- infrared: ISM -- infrared: stars -- ISM: Herbig-Haro objects
© ESO 2004