A Caltech Library Service

Hydrogen Fluoride in High-Mass Star-forming Regions

Emprechtinger, M. and Monje, R. R. and van der Tak, F. F. S. and van der Wiel, M. H. D. and Lis, D. C. and Neufeld, D. and Phillips, T. G. and Ceccarelli, C. (2012) Hydrogen Fluoride in High-Mass Star-forming Regions. Astrophysical Journal, 756 (2). Art. No. 136. ISSN 0004-637X. doi:10.1088/0004-637X/756/2/136.

[img] PDF - Published Version
See Usage Policy.

PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


Hydrogen fluoride (HF) has been established to be an excellent tracer of molecular hydrogen in diffuse clouds. In denser environments, however, the HF abundance has been shown to be approximately two orders of magnitude lower. We present Herschel/HIFI observations of HF J = 1-0 toward two high-mass star formation sites, NGC 6334 I and AFGL 2591. In NGC 6334 I the HF line is seen in absorption in foreground clouds and the source itself, while in AFGL 2591 HF is partially in emission. We find an HF abundance with respect to H_2 of 1.5 × 10^(–8) in the diffuse foreground clouds, whereas in the denser parts of NGC 6334 I we derive a lower limit on the HF abundance of 5 × 10^(–10). Lower HF abundances in dense clouds are most likely caused by freezeout of HF molecules onto dust grains in high-density gas. In AFGL 2591, the view of the hot core is obstructed by absorption in the massive outflow, in which HF is also very abundant (3.6 × 10^(–8)) due to the desorption by sputtering. These observations provide further evidence that the chemistry of interstellar fluorine is controlled by freezeout onto gas grains.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Lis, D. C.0000-0002-0500-4700
Ceccarelli, C.0000-0001-9664-6292
Additional Information:© 2012 The American Astronomical Society. Received 2011 November 1; accepted 2012 June 24; published 2012 August 22. HIFI has been designed and built by a consortium of institutes and university departments from across Europe, Canada, and the United States under the leadership of SRON Netherlands Institute for Space Research, Groningen, The Netherlands, and with major contributions from Germany, France, and the USA. Consortium members are: Canada: CSA, University of Waterloo; France: CESR, LAB, LERMA, IRAM; Germany: KOSMA, MPIfR, MPS; Ireland: NUI Maynooth; Italy: ASI, IFSI-INAF, Osservatorio Astrofisico di Arcetri-INAF; The Netherlands: SRON, TUD; Poland: CAMK, CBK; Spain: Observatorio Astronómico Nacional (IGN), Centro de Astrobiología (CSIC-INTA); Sweden: Chalmers University of Technology—MC2, RSS & GARD, Onsala Space Observatory, Swedish National Space Board, Stockholm University—Stockholm Observatory; Switzerland: ETH Zurich, FHNW; USA: Caltech, JPL, NHSC. We thank many funding agencies for financial support. Support for this work was provided by NASA through an award issued by JPL/Caltech, by l'Agence Nationale pour la Recherche (ANR), France (project FORCOMS, contracts ANR-08-BLAN-022), and the Centre National d'Etudes Spatiales (CNES).
Funding AgencyGrant Number
Agence Nationale pour la Recherche (ANR)ANR-08-BLAN-022
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Subject Keywords:ISM: molecules – stars: formation
Issue or Number:2
Record Number:CaltechAUTHORS:20120716-082451584
Persistent URL:
Official Citation:M. Emprechtinger et al 2012 ApJ 756 136
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:32450
Deposited By: Tony Diaz
Deposited On:26 Jul 2012 23:42
Last Modified:09 Nov 2021 21:27

Repository Staff Only: item control page