| Auteurs | L. Chavarría, F. Herpin, T. Jacq, J. Braine, S. Bontemps, A. Baudry, M. Marseille, F. van der Tak, B. Pietropaoli, F. Wyrowski, R. Shipman, W. Frieswijk, E.F. van Dishoeck, J. Cernicharo, R. Bachiller, M. Benedettini, A.O. Benz, E. Bergin, P. Bjerkeli, G.A. Blake, S. Bruderer, P. Caselli, C. Codella, F. Daniel, A.M. Di Giorgio, C. Dominik, S.D. Doty, P. Encrenaz, M. Fich, A. Fuente, T. Giannini, J.R. Goicoechea, T. de Graauw, P. Hartogh, F. Helmich, G.J. Herczeg, M.R. Hogerheijde, D. Johnstone, J.K. Jørgensen, L.E. Kristensen, B. Larsson, D. Lis, R. Liseau, C. McCoey, G. Melnick, B. Nisini, M. Olberg, B. Parise, J.C. Pearson, R. Plume, C. Risacher, J. Santiago-García, P. Saraceno, J. Stutzki, R. Szczerba, M. Tafalla, A. Tielens, T.A. van Kempen, R. Visser, S.F. Wampfler, J. Willem, U.A. Yıldız | | Titel | Water in massive star-forming regions: HIFI observations of W3 IRS5 |
| Tijdschrift | Astronomy and Astrophysics |
| Jaargang | 521 |
| Jaar | 2010 |
| Pagina's | L37- |
| ISSN | 00046361 |
| Faculteit | Faculteit der Natuurwetenschappen, Wiskunde en Informatica |
| Instituut/afd. | FNWI: Astronomical Institute Anton Pannekoek (IAP) |
| Samenvatting | We present Herschel observations of the water molecule in the massive star-forming region W3 IRS5. The o-(H2O)-O-17 1(10)-1(01), p-(H2O)-O-18 1(11)-0(00), p-H2O 2(02)-1(11), p-H2O 1(11)-0(00), o-H2O 2(21)-2(12), and o-H2O 2(12)-1(01) lines, covering a frequency range from 552 up to 1669 GHz, have been detected at high spectral resolution with HIFI. The water lines in W3 IRS5 show well-defined high-velocity wings that indicate a clear contribution by outflows. Moreover, the systematically blue-shifted absorption in the H2O lines suggests expansion, presumably driven by the outflow. No infall signatures are detected. The p-H2O 1(11)-0(00) and o-H2O 2(12)-1(01) lines show absorption from the cold material (T similar to 10 K) in which the high-mass protostellar envelope is embedded. One-dimensional radiative transfer models are used to estimate water abundances and to further study the kinematics of the region. We show that the emission in the rare isotopologues comes directly from the inner parts of the envelope (T greater than or similar to 100 K) where water ices in the dust mantles evaporate and the gas-phase abundance increases. The resulting jump in the water abundance (with a constant inner abundance of 10(-4)) is needed to reproduce the o-(H2O)-O-17 1(10)-1(01) and p-(H2O)-O-18 1(11)-0(00) spectra in our models. We estimate water abundances of 10(-8) to 10(-9) in the outer parts of the envelope (T less than or similar to 100 K). The possibility of two protostellar objects contributing to the emission is discussed. |
| Soort document | Artikel |
| Download bestand | |
| Document finder | 
|
Gebruik dit adres om naar deze pagina te linken: http://dare.uva.nl/record/374306
Vraag/opmerking over dit recordMail aan een collega
Toevoegen aan bewaarset
|
vorige
