Strong absorption by interstellar hydrogen fluoride: Herschel/HIFI observations of the sight-line to G10.6-0.4 (W31C)
Artikel i vetenskaplig tidskrift, 2010

We report the detection of strong absorption by interstellar hydrogen fluoride along the sight-line to the submillimeter continuum source G10.6-0.4 (W31C). We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 1232.4763 GHz J=1-0 HF transition in the upper sideband of the Band 5a receiver. The resultant spectrum shows weak HF emission from G10.6-0.4 at LSR velocities in the range -10 to -3 km/s, accompanied by strong absorption by foreground material at LSR velocities in the range 15 to 50 km/s. The spectrum is similar to that of the 1113.3430 GHz 1(11)-0(00) transition of para-water, although at some frequencies the HF (hydrogen fluoride) optical depth clearly exceeds that of para-H2O. The optically-thick HF absorption that we have observed places a conservative lower limit of 1.6E+14 cm-2 on the HF column density along the sight-line to G10.6-0.4. Our lower limit on the HF abundance, 6E-9 relative to hydrogen nuclei, implies that hydrogen fluoride accounts for between ~ 30 and 100% of the fluorine nuclei in the gas phase along this sight-line. This observation corroborates theoretical predictions that - because the unique thermochemistry of fluorine permits the exothermic reaction of F atoms with molecular hydrogen - HF will be the dominant reservoir of interstellar fluorine under a wide range of conditions.

Författare

D.A. Neufeld

Johns Hopkins University

P. Sonnentrucker

Johns Hopkins University

T.G. Phillips

California Institute of Technology (Caltech)

D. Lis

California Institute of Technology (Caltech)

M. de Luca

Ecole Normale Superieure (ENS)

J. R. Goicoechea

Centro de Astrobiologia (CAB)

John H Black

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

M. Gerin

Ecole Normale Superieure (ENS)

T. A. Bell

California Institute of Technology (Caltech)

F. Boulanger

Institut d'Astrophysique Spatiale

J. Cernicharo

Centro de Astrobiologia (CAB)

A. Coutens

Université de Toulouse

E. Dartois

Institut d'Astrophysique Spatiale

M. Kazmierczak

Uniwersytet Mikolaja Kopernika

P. Encrenaz

Ecole Normale Superieure (ENS)

E. Falgarone

Ecole Normale Superieure (ENS)

Thomas Geballe

Gemini Observatory North

T. Giesen

Universität zu Köln

B. Godard

Ecole Normale Superieure (ENS)

P.F. Goldsmith

Jet Propulsion Laboratory, California Institute of Technology

C. Gry

Laboratoire d'Astrophysique de Marseille

H. Gupta

Jet Propulsion Laboratory, California Institute of Technology

P. Hennebelle

Ecole Normale Superieure (ENS)

E. Herbst

Ohio State University

P. Hily-Blant

Laboratoire d'Astrophysique de Grenoble

C. Joblin

Université de Toulouse

R. Kolos

Polish Academy of Sciences

J. Krelowski

Uniwersytet Mikolaja Kopernika

J. Martin-Pintado

Centro de Astrobiologia (CAB)

K.M. Menten

Max-Planck-Gesellschaft

Raquel Monje

California Institute of Technology (Caltech)

B. Mookerjea

Tata Institute of Fundamental Research

T. J. Pearson

Jet Propulsion Laboratory, California Institute of Technology

M. Perault

Ecole Normale Superieure (ENS)

Carina Persson

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

R. Plume

University of Calgary

M. Salez

Ecole Normale Superieure (ENS)

S. Schlemmer

Universität zu Köln

M. Schmidt

Polish Academy of Sciences

J. Stutzki

Universität zu Köln

D. Teyssier

European Space Astronomy Centre (ESAC)

C. Vastel

Tata Institute of Fundamental Research

S. Yu

Jet Propulsion Laboratory, California Institute of Technology

P. Cais

Université de Bordeaux

E. Caux

Université de Toulouse

René Liseau

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

P. Morris

Jet Propulsion Laboratory, California Institute of Technology

P. Planesas

Atacama Large Millimeter-submillimeter Array (ALMA)

Astronomy and Astrophysics

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

Vol. 518 4 108- L108

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/201014523

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Senast uppdaterat

2021-11-12