Hydrides in young stellar objects: Radiation tracers in a protostar-disk-outflow system
Journal article, 2010
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 (\sime2500 s) in 8 spectral regions.
Results: The target lines including CH, NH, H_3O^+, and the new molecules SH^+, H_2O^+, and OH^+ are detected. The H_2O^+ 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, H_2O^+ 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. Herschel is an ESA space observatory with science instruments provided by a European-led Principal Investigator consortia and with important participation from NASA.
Author
A. O. Benz
Swiss Federal Institute of Technology in Zürich (ETH)
S. Bruderer
Swiss Federal Institute of Technology in Zürich (ETH)
E. F. van Dishoeck
Leiden University
Max Planck Society
P. Stäuber
Swiss Federal Institute of Technology in Zürich (ETH)
S. F. Wampfler
Swiss Federal Institute of Technology in Zürich (ETH)
M. Melchior
Swiss Federal Institute of Technology in Zürich (ETH)
University of Applied Sciences and Arts Northwestern Switzerland
C. Dedes
Swiss Federal Institute of Technology in Zürich (ETH)
F. Wyrowski
Max Planck Society
S. Doty
Denison University
F. F. S. van der Tak
Netherlands Institute for Space Research (SRON)
University of Groningen
W. Bächtold
Swiss Federal Institute of Technology in Zürich (ETH)
A. Csillaghy
University of Applied Sciences and Arts Northwestern Switzerland
A. Megej
Swiss Federal Institute of Technology in Zürich (ETH)
C. Monstein
Swiss Federal Institute of Technology in Zürich (ETH)
M. Soldati
University of Applied Sciences and Arts Northwestern Switzerland
R. Bachiller
Spanish National Observatory (OAN)
A. Baudry
Institut National des Sciences de l'Univers
Laboratoire d'Astrophysique de Bordeaux
M. Benedettini
University of Rome Tor Vergata
E. A. Bergin
University of Michigan
Per Bjerkeli
Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics
G. A. Blake
California Institute of Technology (Caltech)
S. Bontemps
Institut National des Sciences de l'Univers
Laboratoire d'Astrophysique de Bordeaux
J. Braine
Laboratoire d'Astrophysique de Bordeaux
Institut National des Sciences de l'Univers
P. Caselli
University of Leeds
Arcetri Astrophysical Observatory
J. Cernicharo
Centro de Astrobiologia (CAB)
C. Codella
Arcetri Astrophysical Observatory
F. Daniel
Centro de Astrobiologia (CAB)
A. M. di Giorgio
University of Rome Tor Vergata
P. Dieleman
Netherlands Institute for Space Research (SRON)
C. Dominik
Radboud University
Anton Pannekoek Institute for Astronomy
P. Encrenaz
LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres
M. Fich
University of Waterloo
A. Fuente
Spanish National Observatory (OAN)
T. Giannini
Osservatorio Astronomico di Roma
J. R. Goicoechea
Centro de Astrobiologia (CAB)
T. de Graauw
Netherlands Institute for Space Research (SRON)
F. Helmich
Netherlands Institute for Space Research (SRON)
G. J. Herczeg
Max Planck Society
F. Herpin
Laboratoire d'Astrophysique de Bordeaux
Institut National des Sciences de l'Univers
M. R. Hogerheijde
Leiden University
T. Jacq
Arcetri Astrophysical Observatory
W. Jellema
Netherlands Institute for Space Research (SRON)
D. Johnstone
University of Victoria
National Research Council Canada
J. K. Jorgensen
University of Copenhagen
L. Kristensen
Leiden University
B. Larsson
Stockholm University
D. Lis
California Institute of Technology (Caltech)
René Liseau
Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics
M. Marseille
Netherlands Institute for Space Research (SRON)
C. McCoey
Western University
University of Waterloo
G. J. Melnick
Harvard-Smithsonian Center for Astrophysics
D. A. Neufeld
Johns Hopkins University
B. Nisini
Osservatorio Astronomico di Roma
Michael Olberg
Chalmers, Department of Radio and Space Science, National Facility for Radio Astronomy
V. Ossenkopf
University of Cologne
B. Parise
Max Planck Society
J. C. Pearson
California Institute of Technology (Caltech)
R. Plume
University of Calgary
C. Risacher
Netherlands Institute for Space Research (SRON)
J. Santiago-García
Institut de Radioastronomie Millimétrique (IRAM)
P. Saraceno
University of Rome Tor Vergata
R. Schieder
University of Cologne
R. Shipman
Netherlands Institute for Space Research (SRON)
J. Stutzki
University of Cologne
M. Tafalla
Spanish National Observatory (OAN)
Aggm Tielens
Leiden University
T. A. van Kempen
Harvard-Smithsonian Center for Astrophysics
R. Visser
Leiden University
U. A. Yildiz
Leiden University
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 521 1 L35+- L35Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1051/0004-6361/201015111