1. Odin observations of water in molecular outflows and shocks
- Author
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Per Bjerkeli, Aa. Sandqvist, Edith Falgarone, Göran Olofsson, Åke Hjalmarson, Alain Klotz, Urban Frisk, I. Ristorcelli, René Liseau, Michael Olberg, A. O. H. Olofsson, Bengt Larsson, Onsala Space Observatory, Chalmers University of Technology (OSO), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Swedish Space Corporation (SSC), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Stockholm Observatory, AlbaNova University Center, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
ROTATIONAL-EXCITATION ,WAVE-ASTRONOMY-SATELLITE ,FOS: Physical sciences ,SUPERNOVA REMNANT IC-443 ,Astrophysics ,stars: pre-main sequence ,Volume density ,STAR-FORMATION ,Abundance (ecology) ,Range (statistics) ,SERPENS CLOUD CORE ,Solar and Stellar Astrophysics (astro-ph.SR) ,Line (formation) ,ISM: supernova remnants ,NGC 6334 I ,Physics ,Shock (fluid dynamics) ,SUBMILLIMETER CONTINUUM ,Astronomy and Astrophysics ,TW-HYDRAE ,ISM: molecules ,COLLISIONAL EXCITATION ,Supernova ,ISM: jets and outflows ,BIPOLAR OUTFLOW ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Outflow ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Loss rate - Abstract
Aims. We investigate the ortho-water abundance in outflows and shocks in order to improve our knowledge of shock chemistry and of the physics behind molecular outflows. Methods. We have used the Odin space observatory to observe the H2O(110-101) line. We obtain strip maps and single pointings of 13 outflows and two supernova remnants where we report detections for eight sources. We have used RADEX to compute the beam averaged abundances of o-H2O relative to H2. In the case of non-detection, we derive upper limits on the abundance. Results. Observations of CO emission from the literature show that the volume density of H2 can vary to a large extent, a parameter that puts severe uncertainties on the derived abundances. Our analysis shows a wide range of abundances reflecting the degree to which shock chemistry is affecting the formation and destruction of water. We also compare our results with recent results from the SWAS team. Conclusions. Elevated abundances of ortho-water are found in several sources. The abundance reaches values as high as what would be expected from a theoretical C-type shock where all oxygen, not in the form of CO, is converted to water. However, the high abundances we derive could also be due to the low densities (derived from CO observations) that we assume. The water emission may in reality stem from high density regions much smaller than the Odin beam. We do not find any relationship between the abundance and the mass loss rate. On the other hand, there is a relation between the derived water abundance and the observed maximum outflow velocity., 19 pages, 20 figures, 4 tables
- Published
- 2009