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

CalTech

D. Lis

CalTech

M. de Luca

École Normale Supérieure

J. R. Goicoechea

CSIC-INTA - Centro de Astrobiologia (CAB)

John H Black

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

M. Gerin

École Normale Supérieure

T. A. Bell

CalTech

F. Boulanger

Institut d'Astrophysique Spatiale

J. Cernicharo

CSIC-INTA - Centro de Astrobiologia (CAB)

A. Coutens

Universite de Toulouse

E. Dartois

Institut d'Astrophysique Spatiale

M. Kazmierczak

Uniwersytet Mikołaja Kopernika w Toruniu

P. Encrenaz

École Normale Supérieure

E. Falgarone

École Normale Supérieure

Thomas Geballe

Gemini Telescope

T. Giesen

Universität zu Köln

B. Godard

École Normale Supérieure

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

École Normale Supérieure

E. Herbst

Ohio State University

P. Hily-Blant

Laboratoire d'Astrophysique de Grenoble

C. Joblin

Universite de Toulouse

R. Kolos

Institute of Physical Chemistry of the Polish Academy of Sciences

J. Krelowski

Uniwersytet Mikołaja Kopernika w Toruniu

J. Martin-Pintado

CSIC-INTA - Centro de Astrobiologia (CAB)

K.M. Menten

Max Planck-institutet

Raquel Rodriguez-Monje

CalTech

B. Mookerjea

Tata Institute of Fundamental Research

T. J. Pearson

Jet Propulsion Laboratory, California Institute of Technology

M. Perault

École Normale Supérieure

Carina Persson

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

R. Plume

University of Calgary

M. Salez

École Normale Supérieure

S. Schlemmer

Universität zu Köln

M. Schmidt

Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences

J. Stutzki

Universität zu Köln

D. Teyssier

European Space Astronomy Centre

C. Vastel

Tata Institute of Fundamental Research

S. Yu

Jet Propulsion Laboratory, California Institute of Technology

P. Cais

Universite de Bordeaux

E. Caux

Universite 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

Astronomy and Astrophysics

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

Vol. 518 108- L108

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/201014523