PT Journal
AU Benz, AO
   Bruderer, S
   van Dishoeck, EF
   Stäuber, P
   Wampfler, SF
   Melchior, M
   Dedes, C
   Wyrowski, F
   Doty, SD
   van der Tak, F
   Bächtold, W
   Csillaghy, A
   Megej, A
   Monstein, C
   Soldati, M
   Bachiller, R
   Baudry, A
   Benedettini, M
   Bergin, E
   Bjerkeli, P
   Blake, GA
   Bontemps, S
   Braine, J
   Caselli, P
   Cernicharo, J
   Codella, C
   Daniel, F
   di Giorgio, AM
   Dieleman, P
   Dominik, C
   Encrenaz, P
   Fich, M
   Fuente, A
   Giannini, T
   Goicoechea, JR
   de Graauw, T
   Helmich, F
   Herczeg, GJ
   Herpin, F
   Hogerheijde, MR
   Jacq, T
   Jellema, W
   Johnstone, D
   Jørgensen, JK
   Kristensen, LE
   Larsson, B
   Lis, D
   Liseau, R
   Marseille, M
   McCoey, C
   Melnick, G
   Neufeld, D
   Nisini, B
   Olberg, M
   Ossenkopf, V
   Parise, B
   Pearson, JC
   Plume, R
   Risacher, C
   Santiago-García, J
   Saraceno, P
   Schieder, R
   Shipman, R
   Stutzki, J
   Tafalla, M
   Tielens, AGGM
   van Kempen, TA
   Visser, R
   Yıldız, UA
TI Hydrides in young stellar objects: Radiation tracers in a protostar-disk-outflow system
SO Astron. Astrophys.
PY 2010
BP L35 (1 to 5)
VL 521
DI 10.1051/0004-6361/201015111
DE HEB mixer applications; HIFI; Herschel
AB Context. Hydrides of the most abundant heavier elements are fundamental molecules in cosmic chemistry. Some of them trace gas irradiated by UV or X-rays.Aims. We explore the abundances of major hydrides in W3 IRS5, a prototypical region of high-mass star formation.Methods. W3 IRS5 was observed by HIFI on the Herschel Space Observatory with deep integration (2500 s) in 8 spectral regions.Results. The target lines including CH, NH, H3O+, and the new molecules SH+, H2O+, and OH+ are detected. The H2O+ and OH+ J = 1–0 lines are found mostly in absorption, but also appear to exhibit weak emission (P-Cyg-like). Emission requires high density, thus originates most likely near the protostar. This is corroborated by the absence of line shifts relative to the young stellar object (YSO). In addition, H2O+ and OH+ also contain strong absorption components at a velocity shifted relative to W3 IRS5, which are attributed to foreground clouds.Conclusions. The molecular column densities derived from observations correlate well with the predictions of a model that assumes the main emission region is in outflow walls, heated and irradiated by protostellar UV radiation.
ER