CH+(1-0) and 13CH+(1-0) absorption lines in the direction of massive star-forming regions
Artikel i vetenskaplig tidskrift, 2010
We report the detection of the ground-state rotational transition of the methylidyne cation CH+ and its isotopologue (CH+)-C-13 toward the remote massive star-forming regions W33A, W49N, and W51 with the HIFI instrument onboard the Herschel satellite. Both lines are seen only in absorption against the dust continuum emission of the star-forming regions. The CH+ absorption is saturated over almost the entire velocity ranges sampled by the lines-of-sight that include gas associated with the star-forming regions (SFR) and Galactic foreground material. The CH+ column densities are inferred from the optically thin components. A lower limit of the isotopic ratio [(CH+)-C-12]/[(CH+)-C-13]> 35.5 is derived from the absorptions of foreground material toward W49N. The column density ratio, N(CH+)/N(HCO+), is found to vary by at least a factor 10, between 4 and > 40, in the Galactic foreground material. Line-of-sight 12CH+ average abundances relative to total hydrogen are estimated. Their average value, N(CH+)/NH > 2.6 x 10(-8), is higher than that observed in the solar neighborhood and confirms the high abundances of CH+ in the Galactic interstellar medium. We compare this result to the predictions of turbulent dissipation regions (TDR) models and find that these high abundances can be reproduced for the inner Galaxy conditions. It is remarkable that the range of predicted N(CH+)/ N(HCO+) ratios, from 1 to similar to 50, is comparable to that observed.
ISM: molecules
astrochemistry
ISM: kinematics and dynamics
turbulence
Författare
E. Falgarone
Ecole Normale Superieure (ENS)
B. Godard
Observatoire de Paris
J. Cernicharo
Consejo Superior de Investigaciones Científicas (CSIC)
M. de Luca
Ecole Normale Superieure (ENS)
M. Gerin
Observatoire de Paris
T.G. Phillips
California Institute of Technology (Caltech)
John H Black
Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik
D. Lis
Jet Propulsion Laboratory, California Institute of Technology
T. A. Bell
Consejo Superior de Investigaciones Científicas (CSIC)
F. Boulanger
Ecole Normale Superieure (ENS)
A. Coutens
Université de Bordeaux
E. Dartois
Université Paris-Saclay
P. Encrenaz
Observatoire de Paris
T. Giesen
Universität Kassel
J.R. Goicoechea
Consejo Superior de Investigaciones Científicas (CSIC)
P.F. Goldsmith
Jet Propulsion Laboratory, California Institute of Technology
H. Gupta
National Science Foundation
C. Gry
Laboratoire d'Astrophysique de Marseille
P. Hennebelle
Ecole Normale Superieure (ENS)
E. Herbst
University of Virginia
P. Hily-Blant
Université Grenoble Alpes
C. Joblin
National Museum of Botswana
M. Kazmierczak
Netherlands Institute for Space Research (SRON)
R. Kolos
Polish Academy of Sciences
J. Krelowski
University of Rzeszów
J. Martin-Pintado
Instituto Nacional de Tecnica Aeroespacial
Raquel Monje
Jet Propulsion Laboratory, California Institute of Technology
B. Mookerjea
Tata Institute of Fundamental Research
D.A. Neufeld
Johns Hopkins University
M. Perault
Ecole Normale Superieure (ENS)
J. C. Pearson
Jet Propulsion Laboratory, California Institute of Technology
Carina Persson
Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik
R. Plume
University of Calgary
M. Salez
Centre national de la recherche scientifique (CNRS)
M. Schmidt
Polish Academy of Sciences
P. Sonnentrucker
Space Telescope Science Institute (STScI)
J. Stutzki
Universität zu Köln
D. Teyssier
Europeiska rymdorganisationen (ESA)
C. Vastel
Universite Paul Sabatier Toulouse III
S. Yu
Jet Propulsion Laboratory, California Institute of Technology
K. M. Menten
Max-Planck-Gesellschaft
T. R. Geballe
Gemini Observatory North
S. Schlemmer
Universität zu Köln
R. Shipman
Netherlands Institute for Space Research (SRON)
A.G.G.M. Tielens
Universiteit Leiden
S. Philipp
Max-Planck-Gesellschaft
A. Cros
Universidad de Guadalajara
J. Zmuidzinas
California Institute of Technology (Caltech)
L.A. Samoska
Jet Propulsion Laboratory, California Institute of Technology
K. Klein
University of Arizona
A. Lorenzani
Istituto nazionale di astrofisica (INAF)
R. Szczerba
Polish Academy of Sciences
I. Peron
Institut de Radioastronomie Millimétrique (IRAM)
P. Cais
Université de Bordeaux
P. Gaufre
Laboratoire d'Astrophysique de Bordeaux
L. Ravera
Institut de Recherche en Astrophysique et Planétologie (IRAP)
P. Morris
California Institute of Technology (Caltech)
S. Lord
California Institute of Technology (Caltech)
P. Planesas
Observatorio Astronómico Nacional (OAN)
A. Cros
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 521 1 L15Ämneskategorier (SSIF 2011)
Astronomi, astrofysik och kosmologi
Fundament
Grundläggande vetenskaper
DOI
10.1051/0004-6361/201015109