Letter to the Editor

Highlights from the first year of Odin observations^*

¹ Onsala Space Observatory, 439 92 Onsala, Sweden
² Swedish Space Corporation, PO Box 4207, 171 04 Solna, Sweden
³ Department of Physics, University of Waterloo, Waterloo, ON N2L 3G1, Canada
⁴ ESA-ESTEC, Keplerlaan 1, 2200 AG, Noordwijk, The Netherlands
⁵ LESIA & FRE 2461 de CNRS, Observatoire de Paris, 5 place Jules Janssen, 92195 Meudon Cedex, France
⁶ Laboratoire d'Astronomie Spatiale, BP 8, 13376 Marseille Cedex 12, France
⁷ LERMA & FRE 2460 du CNRS, Observatoire de Paris, 61 Av. de l'Observatoire, 75140 Paris, France
⁸ LERMA & FRE 2460 du CNRS, École Normale Supérieure, 24 rue Lhomond, 75005 Paris, France
⁹ NRC Canada, Herzberg Inst. of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7, Canada
¹⁰ Stockholm Observatory, SCFAB, Roslagstullsbacken 21, 106 91 Stockholm, Sweden
¹¹ Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
¹² Observatory, PO Box 14, University of Helsinki, 00014 Helsinki, Finland
¹³ Department of Physics and Astronomy, University of Calgary, Calgary, ABT 2N 1N4, Canada
¹⁴ Finnish Meteorological Institute, PO Box 503, 00101 Helsinki, Finland
¹⁵ Metsähovi Radio Observatory, Helsinki University of Technology, Otakaari 5A, 02150 Espoo, Finland
¹⁶ Department of Physics and Engineering Physics, 116 Science Place, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
¹⁷ Institut Pierre Simon Laplace, CNRS-Université Paris 6, 4 place Jussieu, 75252 Paris Cedex 05, France
¹⁸ Department of Astronomy and Physics, Saint Mary's University, Halifax, NS B3H 3C3, Canada
¹⁹ Global Environmental Measurements Group, Chalmers University of Technology, 412 96 Göteborg, Sweden
²⁰ ESO, Casilla 19001, Santiago 19, Chile
²¹ Swedish National Space Board, PO Box 4006, 171 04 Solna, Sweden
²² Uppsala Astronomical Observatory, Box 515, 751 20 Uppsala, Sweden
²³ CESR, 9 Avenue du Colonel Roche, BP 4346, 31029 Toulouse, France
²⁴ Canadian Space Agency, St-Hubert, J3Y 8Y9, Québec, Canada
²⁵ Department of Meteorology, Stockholm University, 106 91 Stockholm, Sweden

Corresponding author: Å. Hjalmarson, hjalmar@oso.chalmers.se

Received: 3 December 2002
Accepted: 28 January 2003

Abstract

Key Odin operational and instrumental features and highlights from our sub-millimetre and millimetre wave observations of H₂O, HO, NH₃, ¹⁵NH₃ and O₂ are presented, with some insights into accompanying Odin Letters in this A&A issue. We focus on new results where Odin's high angular resolution, high frequency resolution, large spectrometer bandwidths, high sensitivity or/and frequency tuning capability are crucial: H₂O mapping of the Orion KL, W 3, DR 21, S 140 regions, and four comets; H₂O observations of Galactic Centre sources, of shock enhanced H₂O towards the SNR IC 443, and of the candidate infall source IRAS 16293-2422; HO detections in Orion KL and in comet Ikeya-Zhang; sub-mm detections of NH₃ in Orion KL (outflow, ambient cloud and bar) and ρ  Oph, and very recently, of ¹⁵NH₃ in Orion KL. Simultaneous sensitive searches for the 119 GHz line of O₂ have resulted in very low abundance limits, which are difficult to accomodate in chemical models. We also demonstrate, by means of a quantitative comparison of Orion KL H₂O results, that the Odin and SWAS observational data sets are very consistently calibrated.