Molecular oxygen in the rho Ophiuchi cloud
Bengt Larsson
(1)
,
René Liseau
(1)
,
Laurent Pagani
(2)
,
Per Bergman
(3)
,
Peter Bernath
(4)
,
Nicolas Biver
(5, 6, 7)
,
John H. Black
(3)
,
R. S. Booth
(3)
,
Véronique Buat
(8)
,
Jacques Crovisier
(5, 6, 7)
,
Charles Curry
(4)
,
M. Dahlgren
(3)
,
Pierre J. Encrenaz
(2)
,
Edith Falgarone
(2)
,
P. A. Feldman
(9)
,
Michael Fich
(4)
,
Hans-Gustav Florén
(1)
,
M. Fredrixon
(3)
,
Urban Frisk
(10)
,
G. F. Gahm
(1)
,
Maryvonne Gerin
(2)
,
M. Hagström
(3)
,
J. Harju
(11)
,
Tatsuhiko Hasegawa
(12)
,
Åke Hjalmarson
(3)
,
Lars E. B. Johansson
(3)
,
Kay Justtanont
(1)
,
Alain Klotz
(13)
,
Erkki Kyrölä
(14)
,
Sun Kwok
(12)
,
Alain Lecacheux
(5, 6, 7)
,
T. Liljeström
(15)
,
Edward J. Llewellyn
(16)
,
Stefan Lundin
(10)
,
Gérard Megie
(17)
,
G. F. Mitchell
(18)
,
Donal Murtagh
(19)
,
H. Lennart Nordh
(20)
,
L.-Å. Nyman
(21)
,
Michael Olberg
(3)
,
Henrik Olofsson
(3)
,
Goran Olofsson
(1)
,
H. Olofsson
(1)
,
Glenn Persson
(3)
,
René Plume
(12)
,
Hans Rickman
(22)
,
I. Ristorcelli
(13)
,
Gustaf Rydbeck
(3)
,
Aage Sandqvist
(1)
,
F. V. Schéele
(10)
,
G. Serra
(13)
,
Stephen A. Torchinsky
(23)
,
N. F. H. Tothill
(18)
,
Kathryn Volk
(12)
,
Tommy Wiklind
(3)
,
Christine D. Wilson
(24)
,
Anders Winnberg
(3)
,
Georg Witt
(25)
1
Stockholm Observatory, AlbaNova University Center
2 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique
3 OSO - Onsala Space Observatory, Chalmers University of Technology
4 University of Waterloo [Waterloo]
5 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
6 Physique des plasmas
7 Pôle Planétologie du LESIA
8 LAS - Laboratoire d'Astronomie Spatiale
9 National Research Council of Canada (NRC)
10 SSC - Swedish Space Corporation
11 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
12 University of Calgary
13 CESR - Centre d'étude spatiale des rayonnements
14 FMI - Finnish Meteorological Institute
15 Metsähovi Radio Observatory
16 U of S - University of Saskatchewan [Saskatoon, Canada]
17 IPSL (FR_636) - Institut Pierre-Simon-Laplace
18 Department of Astronomy and Physics, Saint Mary's University
19 Global Environmental Measurements Group
20 SNSB - Swedish National Space Board
21 APEX team, ESO, Santiago
22 Uppsala Astronomical Observatory
23 CSA - Canadian Space Agency
24 Department of Physics and Astronomy, McMaster University
25 Stockholm University
2 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique
3 OSO - Onsala Space Observatory, Chalmers University of Technology
4 University of Waterloo [Waterloo]
5 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
6 Physique des plasmas
7 Pôle Planétologie du LESIA
8 LAS - Laboratoire d'Astronomie Spatiale
9 National Research Council of Canada (NRC)
10 SSC - Swedish Space Corporation
11 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
12 University of Calgary
13 CESR - Centre d'étude spatiale des rayonnements
14 FMI - Finnish Meteorological Institute
15 Metsähovi Radio Observatory
16 U of S - University of Saskatchewan [Saskatoon, Canada]
17 IPSL (FR_636) - Institut Pierre-Simon-Laplace
18 Department of Astronomy and Physics, Saint Mary's University
19 Global Environmental Measurements Group
20 SNSB - Swedish National Space Board
21 APEX team, ESO, Santiago
22 Uppsala Astronomical Observatory
23 CSA - Canadian Space Agency
24 Department of Physics and Astronomy, McMaster University
25 Stockholm University
Résumé
Context: Molecular oxygen, O2, has been expected historically to be an abundant component of the chemical species in molecular clouds and, as such, an important coolant of the dense interstellar medium. However, a number of attempts from both ground and from space have failed to detect O2 emission.
Aims: The work described here uses heterodyne spectroscopy from space to search for molecular oxygen in the interstellar medium.
Methods: The Odin satellite carries a 1.1 m sub-millimeter dish and a dedicated 119 GHz receiver for the ground state line of O2. Starting in 2002, the star forming molecular cloud core rho {Oph A} was observed with Odin for 34 days during several observing runs.
Results: We detect a spectral line at v_LSR =+3.5 km s-1 with Delta v_FWHM=1.5 km s-1, parameters which are also common to other species associated with rho {Oph A}. This feature is identified as the O2 (NJ = 11 - 1_0) transition at 118 750.343 MHz.
Conclusions: The abundance of molecular oxygen, relative to H{2} , is 5 × 10-8 averaged over the Odin beam. This abundance is consistently lower than previously reported upper limits.
Aims: The work described here uses heterodyne spectroscopy from space to search for molecular oxygen in the interstellar medium.
Methods: The Odin satellite carries a 1.1 m sub-millimeter dish and a dedicated 119 GHz receiver for the ground state line of O2. Starting in 2002, the star forming molecular cloud core rho {Oph A} was observed with Odin for 34 days during several observing runs.
Results: We detect a spectral line at v_LSR =+3.5 km s-1 with Delta v_FWHM=1.5 km s-1, parameters which are also common to other species associated with rho {Oph A}. This feature is identified as the O2 (NJ = 11 - 1_0) transition at 118 750.343 MHz.
Conclusions: The abundance of molecular oxygen, relative to H{2} , is 5 × 10-8 averaged over the Odin beam. This abundance is consistently lower than previously reported upper limits.
Domaines
Astrophysique [astro-ph]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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