EDP Sciences
Free access
Volume 407, Number 2, August IV 2003
Page(s) 589 - 607
Section Formation, structure and evolution of stars
DOI http://dx.doi.org/10.1051/0004-6361:20030841

A&A 407, 589-607 (2003)
DOI: 10.1051/0004-6361:20030841

A spectral survey of the Orion Nebula from 455-507 GHz

Glenn J. White1, 2, 3, M. Araki4, J. S. Greaves5, M. Ohishi6 and N. S. Higginbottom7

1  Centre for Astrophysics & Planetary Science, University of Kent, Canterbury, Kent CT2 7NR, UK
2  Stockholm Observatory, 133 36 Saltsjöbaden, Sweden
3  Astrophysics Group, The Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 OHE, UK
4  Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
5  Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
6  National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588, Japan
7  Department of Physics, Queen Mary & Westfield College, University of London, Mile End Road, London E1 4NS, UK

(Received 11 June 2002 / Accepted 22 May 2003 )

The results of a submillimetre wavelength spectral line survey between 455.1-507.4 GHz of the Orion-KL hot cloud core are reported. A total of 254 lines were detected to a main beam brightness temperature sensitivity $T_{\rm mb}\,$~ 1-3 K. The detected lines are identified as being associated with 30 different molecular species or their isotopomeric variants. The strongest line detected was the J = 4-3 transition of the CO molecule. Apart from abundant diatomic rotors such as CO and CS, the spectrum is dominated by SO, SO $_{\rm 2}$ and CH $_{\rm 3}$OH and large organic molecules such as (CH 3) 2O, CH $_{\rm 3}$CN, C $_{\rm 2}$H $_{\rm 3}$CN, C $_{\rm 2}$H $_{\rm 5}$CN and HCOOCH $_{\rm 3}$ which make up ~72% of the total number of lines; unidentified lines ~13%; and other lines the remaining ~15% of the total. Rotational temperatures and column densities derived using standard rotation diagram analysis techniques were found to range from 70-300 K, and 10 14-10 $^{{\rm 17}}$ cm $^{\rm 2}$ respectively.

Key words: molecules -- star formation -- molecular cloud

Offprint request: Glenn J. White, g.j.white@kent.ac.uk

SIMBAD Objects

© ESO 2003