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

Centro Astronomico de Yebes

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 Institute

S. Cabrit

LUTH - Laboratoire de l'Univers et de ses Theories

N. R. Crockett

University of Michigan

F. Daniel

LUTH - Laboratoire de l'Univers et de ses Theories

Centro de Astrobiologia (CAB)

E. Falgarone

LUTH - Laboratoire de l'Univers et de ses Theories

M. C. Diez-Gonzalez

Centro Astronomico de Yebes

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 Institute

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

University of Cologne

Netherlands Institute for Space Research (SRON)

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

Max Planck Institute

University of Cologne

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

LUTH - Laboratoire de l'Univers et de ses Theories

University of Toulouse

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 Institute

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+- L47

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

DOI

10.1051/0004-6361/201015117

More information

Latest update

10/30/2018