Highlights from the first year of Odin observations

Abstract

Key Odin operational and instrumental features and highlights from our sub-millimetre and millimetre wave observations of H 2O, H 2 18O, NH 3, 15NH 3 and O 2 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: H 2O mapping of the Orion KL, W3, DR 21, S 140 regions, and four comets; H 2O observations of Galactic Centre sources, of shock enhanced H 2O towards the SNR IC 443, and of the candidate infall source IRAS 16293-2422; H 2 18O detections in Orion KL and in comet Ikeya-Zhang; sub-mm detections of NH 3 in Orion KL (outflow, ambient cloud and bar) and ρ Oph, and very recently, of 15NH 3 in Orion KL. Simultaneous sensitive searches for the 119 GHz line of O 2 have resulted in very low abundance limits, which are difficult to accommodate in chemical models. We also demonstrate, by means of a quantitative comparison of Orion KL H 2O results, that the Odin and SWAS observational data sets are very consistently calibrated.