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: molecules
ISM: clouds
ISM: general
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
California Institute of Technology (Caltech)
T.G. Phillips
California Institute of Technology (Caltech)
T. A. Bell
California Institute of Technology (Caltech)
P. Sonnentrucker
Johns Hopkins University
F. Boulanger
Institut d'Astrophysique Spatiale
J. Cernicharo
Centro de Astrobiologia (CAB)
A. Coutens
Centre national de la recherche scientifique (CNRS)
Université de Toulouse
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
Centre national de la recherche scientifique (CNRS)
Université de Toulouse
M. Kazmierczak
Uniwersytet Mikolaja Kopernika
R. Kolos
Polish Academy of Sciences
J. Krelowski
Uniwersytet Mikolaja Kopernika
J. Martin-Pintado
Centro de Astrobiologia (CAB)
Raquel 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 (ESAC)
J. Stutzki
Universität zu Köln
D. Teyssier
MPI fur Extraterrestrische Physik
C. Vastel
Centre national de la recherche scientifique (CNRS)
Université de Toulouse
S. Yu
Jet Propulsion Laboratory, California Institute of Technology
A. Contursi
Max-Planck-Gesellschaft
K. Menten
Gemini Observatory North
Thomas Geballe
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 Observatory North
A. Cros
Centre national de la recherche scientifique (CNRS)
Université de Toulouse
J. Zmuidzinas
California Institute of Technology (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- L110Ämneskategorier
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/201014576