Hydrides in young stellar objects: Radiation tracers in a protostar-disk-outflow system

Benz, A.; Bruderer, S.; van Dishoeck, E.; Staeuber, P.; Wampfler, S.; Melchior, M.; Dedes, C.; Wyrowski, F.; Doty, S.; van der Tak, F.; Baechtold, W.; Csillaghy, A.; Megej, A.; Monstein, C.; Soldati, M.; Bachiller, R.; Baudry, A.; Benedettini, M.; Bergin, E.; Bjerkeli, P.; Blake, G.; Bontemps, S.; Braine, J.; Caselli, P.; Cernicharo, J.; Codella, C.; Daniel, F.; di Giorgio, A.; Dieleman, P.; Dominik, C.; Encrenaz, P.; Fich, M.; Fuente, A.; Giannini, T.; Goicoechea, J.; de Graauw, Th.; Helmich, F.; Herczeg, G.; Herpin, F.; Hogerheijde, M.; Jacq, T.; Jellema, W.; Johnstone, D.; Jorgensen, J.; Kristensen, L.; Larsson, B.; Lis, D.; Liseau, R.; Marseille, M.; McCoey, C.; Melnick, G.; Neufeld, D.; Nisini, B.; Olberg, M.; Ossenkopf, V.; Parise, B.; Pearson, J.; Plume, R.; Risacher, C.; Santiago-Garcia, J.; Saraceno, P.; Schieder, R.; Shipman, R.; Stutzki, J.; Tafalla, M.; Tielens, A.; van Kempen, T.; Visser, R.; Yildiz, UMUT

doi:10.1051/0004-6361/201015111

Hydrides in young stellar objects: Radiation tracers in a protostar-disk-outflow system

Benz A. O., Bruderer S., van Dishoeck E. F., Staeuber P., Wampfler S. F., Melchior M., ...Daha Fazla

ASTRONOMY & ASTROPHYSICS, cilt.521, 2010 (SCI-Expanded, Scopus)

Yayın Türü: Makale / Tam Makale
Cilt numarası: 521
Basım Tarihi: 2010
Doi Numarası: 10.1051/0004-6361/201015111
Dergi Adı: ASTRONOMY & ASTROPHYSICS
Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

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 (similar or equal to 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.