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Odin observations of water in molecular outflows and shocks
- Source :
- Astronomy & astrophysics, 507(3), 1455-U296. EDP Sciences, Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, 2009, 507, pp.1455-1466. ⟨10.1051/0004-6361/200912064⟩
- Publication Year :
- 2009
-
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.<br />19 pages, 20 figures, 4 tables
- 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
Subjects
Details
- Language :
- English
- ISSN :
- 00046361
- Database :
- OpenAIRE
- Journal :
- Astronomy & astrophysics, 507(3), 1455-U296. EDP Sciences, Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, 2009, 507, pp.1455-1466. ⟨10.1051/0004-6361/200912064⟩
- Accession number :
- edsair.doi.dedup.....f993ab6671dc72667bb6c27988a7a067