Detection of OH+ and H2O+ towards Orion KL
Journal article, 2010
We report observations of the reactive molecular ions OH^+, H_2O^+, and H_3O^+ towards Orion KL with Herschel/HIFI. All three N = 1-0 fine-structure transitions of OH^+ at 909, 971, and 1033 GHz and both fine-structure components of the doublet ortho-H_2O^+ 1_11-0_00 transition at 1115 and 1139 GHz were detected; an upper limit was obtained for H_3O^+. OH^+ and H_2O^+ are observed purely in absorption, showing a narrow component at the source velocity of 9 km s^-1, and a broad blueshifted absorption similar to that reported recently for HF and para-H_2^18O, and attributed to the low velocity outflow of Orion KL. We estimate column densities of OH^+ and H_2O^+ for the 9 km s^-1 component of 9 \plusmn 3 \times 10^12 cm^-2 and 7 \plusmn 2 \times 10^12 cm^-2, and those in the outflow of 1.9 \plusmn 0.7 \times 10^13 cm^-2 and 1.0 \plusmn 0.3 \times 10^13 cm^-2. Upper limits of 2.4 \times 10^12 cm^-2 and 8.7 \times 10^12 cm^-2 were derived for the column densities of ortho and para-H_3O^+ from transitions near 985 and 1657 GHz. The column densities of the three ions are up to an order of magnitude lower than those obtained from recent observations of W31C and W49N. The comparatively low column densities may be explained by a higher gas density despite the assumption of a very high ionization rate.
Author
H. Gupta
Jet Propulsion Laboratory, California Institute of Technology
P. B. Rimmer
Ohio State University
J. C. Pearson
Jet Propulsion Laboratory, California Institute of Technology
S. Yu
Jet Propulsion Laboratory, California Institute of Technology
E. Herbst
Ohio State University
N. Harada
Ohio State University
E. A. Bergin
University of Michigan
D. A. Neufeld
Johns Hopkins University
G. J. Melnick
Harvard-Smithsonian Center for Astrophysics
R. Bachiller
Yebes Observatory
W. Baechtold
Swiss Federal Institute of Technology in Zürich (ETH)
T. A. Bell
California Institute of Technology (Caltech)
G. A. Blake
California Institute of Technology (Caltech)
E. Caux
LUTH - Laboratoire de l'Univers et de ses Theories
University of Toulouse
C. Ceccarelli
Laboratoire d'Astrophysique de l'Observatoire de Grenoble
J. Cernicharo
Centro de Astrobiologia (CAB)
Goutam Chattopadhyay
Jet Propulsion Laboratory, California Institute of Technology
C. Comito
Max Planck Society
S. Cabrit
LUTH - Laboratoire de l'Univers et de ses Theories
N. R. Crockett
University of Michigan
F. Daniel
Centro de Astrobiologia (CAB)
LUTH - Laboratoire de l'Univers et de ses Theories
E. Falgarone
LUTH - Laboratoire de l'Univers et de ses Theories
M. C. Diez-Gonzalez
Yebes Observatory
M.-L. Dubernet
LUTH - Laboratoire de l'Univers et de ses Theories
N. Erickson
University of Massachusetts
M. Emprechtinger
California Institute of Technology (Caltech)
P. Encrenaz
LUTH - Laboratoire de l'Univers et de ses Theories
M. Gerin
LUTH - Laboratoire de l'Univers et de ses Theories
John Gill
Jet Propulsion Laboratory, California Institute of Technology
T. F. Giesen
University of Cologne
J. R. Goicoechea
Centro de Astrobiologia (CAB)
P. F. Goldsmith
Jet Propulsion Laboratory, California Institute of Technology
C. Joblin
LUTH - Laboratoire de l'Univers et de ses Theories
University of Toulouse
D. Johnstone
National Research Council Canada
W. D. Langer
Jet Propulsion Laboratory, California Institute of Technology
B. Larsson
Stockholm University
W. B. Latter
California Institute of Technology (Caltech)
Robert Lin
Jet Propulsion Laboratory, California Institute of Technology
D. C. Lis
California Institute of Technology (Caltech)
René Liseau
Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics
S. D. Lord
California Institute of Technology (Caltech)
F. W. Maiwald
Jet Propulsion Laboratory, California Institute of Technology
S. Maret
Laboratoire d'Astrophysique de l'Observatoire de Grenoble
P. G. Martin
Canadian Institute for Theoretical Astrophysics
J. Martin-Pintado
Centro de Astrobiologia (CAB)
K. M. Menten
Max Planck Society
P. Morris
California Institute of Technology (Caltech)
H. S. P. Müller
University of Cologne
J. A. Murphy
Maynooth University
L. H. Nordh
Stockholm University
Michael Olberg
Chalmers, Department of Radio and Space Science, National Facility for Radio Astronomy
V. Ossenkopf
Netherlands Institute for Space Research (SRON)
University of Cologne
L. Pagani
LUTH - Laboratoire de l'Univers et de ses Theories
M. Pérault
LUTH - Laboratoire de l'Univers et de ses Theories
T. G. Phillips
California Institute of Technology (Caltech)
R. Plume
University of Calgary
S.-L. Qin
University of Cologne
M. Salez
LUTH - Laboratoire de l'Univers et de ses Theories
A. Samoska
Jet Propulsion Laboratory, California Institute of Technology
P. Schilke
University of Cologne
Max Planck Society
Erich Schlecht
Jet Propulsion Laboratory, California Institute of Technology
S. Schlemmer
University of Cologne
R. Szczerba
Polish Academy of Sciences
J. Stutzki
University of Cologne
N. Trappe
Maynooth University
F. F. S. van der Tak
Netherlands Institute for Space Research (SRON)
C. Vastel
University of Toulouse
LUTH - Laboratoire de l'Univers et de ses Theories
S. Wang
University of Michigan
H. W. Yorke
Jet Propulsion Laboratory, California Institute of Technology
J. Zmuidzinas
California Institute of Technology (Caltech)
A. Boogert
California Institute of Technology (Caltech)
R. Güsten
Max Planck Society
P. Hartogh
MPI für Sonnensystemforschung
N. Honingh
National Research Council Canada
A. Karpov
California Institute of Technology (Caltech)
J. Kooi
California Institute of Technology (Caltech)
J.-M. Krieg
Centro de Astrobiologia (CAB)
R. Schieder
University of Cologne
P. Zaal
Netherlands Institute for Space Research (SRON)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 521 1 L47+- L47Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1051/0004-6361/201015117