Interstellar OH+, H2O+ and H3O+ along the sight-line to G10.6-0.4
Artikel i vetenskaplig tidskrift, 2010

We report the detection of absorption lines by the reactive ions OH+, H2O+ and H3O+ along the line of sight to the submillimeter continuum source G10.6$-$0.4 (W31C). We used the Herschel HIFI instrument in dual beam switch mode to observe the ground state rotational transitions of OH+ at 971 GHz, H2O+ at 1115 and 607 GHz, and H3O+ at 984 GHz. The resultant spectra show deep absorption over a broad velocity range that originates in the interstellar matter along the line of sight to G10.6$-$0.4 as well as in the molecular gas directly associated with that source. The OH+ spectrum reaches saturation over most velocities corresponding to the foreground gas, while the opacity of the H2O+ lines remains lower than 1 in the same velocity range, and the H3O+ line shows only weak absorption. For LSR velocities between 7 and 50 kms$^{-1}$ we estimate total column densities of $N$(OH+) $> 2.5 \times 10^{14}$ cm$^{-2}$, $N$(H2O+) $\sim 6 \times 10^{13}$ cm$^{-2}$ and $N$(H3O+) $\sim 4.0 \times 10^{13}$ cm$^{-2}$. These detections confirm the role of O$^+$ and OH$^+$ in initiating the oxygen chemistry in diffuse molecular gas and strengthen our understanding of the gas phase production of water. The high ratio of the OH+ by the H2O+ column density implies that these species predominantly trace low-density gas with a small fraction of hydrogen in molecular form.

ISM: general

ISM: molecules

ISM: clouds

Författare

M. Gerin

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

M. de Luca

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

John H Black

Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik

J.R. Goicoechea

Centro de Astrobiologia (CAB)

E. Herbst

Ohio State University

D.A. Neufeld

Johns Hopkins University

E. Falgarone

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

B. Godard

Institut d'Astrophysique Spatiale

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

T. J. Pearson

Jet Propulsion Laboratory, California Institute of Technology

D. Lis

CalTech

T.G. Phillips

CalTech

T. A. Bell

CalTech

P. Sonnentrucker

Johns Hopkins University

F. Boulanger

Institut d'Astrophysique Spatiale

J. Cernicharo

Centro de Astrobiologia (CAB)

A. Coutens

Université de Toulouse

Centre national de la recherche scientifique (CNRS)

E. Dartois

Institut d'Astrophysique Spatiale

P. Encrenaz

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

T. Giesen

Universität zu Köln

P.F. Goldsmith

Jet Propulsion Laboratory, California Institute of Technology

H. Gupta

Jet Propulsion Laboratory, California Institute of Technology

C. Gry

Laboratoire d'Astrophysique de Marseille

P. Hennebelle

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

P. Hily-Blant

Laboratoire d'Astrophysique de Grenoble

C. Joblin

Université de Toulouse

Centre national de la recherche scientifique (CNRS)

M. Kazmierczak

Uniwersytet Mikołaja Kopernika w Toruniu

R. Kolos

Institute of Physical Chemistry of the Polish Academy of Sciences

J. Krelowski

Uniwersytet Mikołaja Kopernika w Toruniu

J. Martin-Pintado

Centro de Astrobiologia (CAB)

Raquel Rodriguez-Monje

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

B. Mookerjea

Tata Institute of Fundamental Research

M. Perault

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

Carina Persson

Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik

R. Plume

University of Calgary

P. B. Rimmer

Ohio State University

M Salez

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

M. Schmidt

European Space Astronomy Centre (ESA)

J. Stutzki

Universität zu Köln

D. Teyssier

MPI fur Extraterrestrische Physik

C. Vastel

Université de Toulouse

Centre national de la recherche scientifique (CNRS)

S. Yu

Jet Propulsion Laboratory, California Institute of Technology

A. Contursi

Max Planck-institutet

K. Menten

Gemini Telescope

Thomas Geballe

Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences

S. Schlemmer

Universität zu Köln

R. Shipman

Netherlands Institute for Space Research (SRON)

A.G.G.M. Tielens

S. Philipp-May

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

Gemini Telescope

A. Cros

Centre national de la recherche scientifique (CNRS)

Université de Toulouse

J. Zmuidzinas

CalTech

L.A. Samoska

Jet Propulsion Laboratory, California Institute of Technology

K. Klein

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

A. Lorenzani

Osservatorio Astrofisico di Arcetri

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 518 4 110- L110

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/201014576