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| EPoS Contribution |
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Results from the HEXOS Full Band Spectral Survey of Orion South
Rene Plume U Calgary, Calgary, CA | |
| Orion South is located 2' south of its more famous cousin, Orion KL. Nevertheless, Orion South is an interesting region in its own right. Highly colimated outflows, SiO emission, and an IR luminosity that is ten times lower than KL, indicate the presence of embedded star formation at an early phase. In addition, the spectral lines in Orion South are narrower than those in Orion KL, suggesting that the gas is also more quiescent in nature. Finally, the chemistry in Orion South is more similar to that seen in the quiescent ridge of Orion KL, than it is to the hot core or plateau. All of this evidence together suggests that Orion South is a younger more quiescent massive star forming region. Since Orion South and KL both formed from the same Giant Molecular Cloud this provides an excellent opportunity to study the evolution of a massive star forming region. I will present results from the full band spectral survey of Orion South, taken as part of the HEXOS (Herschel observations of EXtraordinary ObjectS) Guaranteed Time Key Project. From ~ 500 - 1900 GHz we identify and fit over 600 strong (S/N > 5) spectral lines from 47 different species. Using LTE spectral line profile fitting, we have been able to obtain the column densities, excitation temperatures, and size of the emission region for each of the observed species. In addition, we have made the first species-by-species comparison with the different physical components of Orion KL allowing us to directly compare the chemical differences between Orion South and KL: two different massive star forming regions at different ages. | |
| Collaborators: K. Tahani, UCalgary, Canada E. Bergin, UMichigan, USA HEXOS Key Project Team |
Suggested Session:
Chemistry |