CH+(1-0) and 13CH+(1-0) absorption lines in the direction of massive star-forming regions
Journal article, 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.

turbulence

ISM: molecules

astrochemistry

ISM: kinematics and dynamics

Author

E. Falgarone

Ecole Normale Superieure (ENS)

B. Godard

Paris Observatory

J. Cernicharo

CSIC - Instituto de Fisica Fundamental (IFF)

M. de Luca

Ecole Normale Superieure (ENS)

M. Gerin

Paris Observatory

T.G. Phillips

California Institute of Technology (Caltech)

John H Black

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

D. Lis

Jet Propulsion Laboratory, California Institute of Technology

T. A. Bell

Spanish Astrobiology Center (INTA-CSIC)

F. Boulanger

Ecole Normale Superieure (ENS)

A. Coutens

University of Bordeaux

E. Dartois

University Paris-Saclay

P. Encrenaz

Paris Observatory

T. Giesen

Universitat Kassel

J.R. Goicoechea

CSIC - Instituto de Fisica Fundamental (IFF)

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

Grenoble Alpes University

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, Earth and Space Sciences, Radio Astronomy and Astrophysics

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

University of Cologne

D. Teyssier

European Space Agency (ESA)

C. Vastel

Paul Sabatier University

S. Yu

Jet Propulsion Laboratory, California Institute of Technology

K. M. Menten

Max-Planck Institute for Radio Astronomy

T. R. Geballe

Gemini Observatory North

S. Schlemmer

University of Cologne

R. Shipman

Netherlands Institute for Space Research (SRON)

A.G.G.M. Tielens

Leiden University

S. Philipp

Max-Planck Institute for Radio Astronomy

A. Cros

University of 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

University of 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

Spanish National Observatory (OAN)

A. Cros

Institut de Recherche en Astrophysique et Planétologie (IRAP)

Astronomy and Astrophysics

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

Vol. 521 1 L15

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

DOI

10.1051/0004-6361/201015109

More information

Latest update

7/8/2021 1