Water in low-mass star-forming regions with Herschel. HIFI spectroscopy of NGC 1333
Artikel i vetenskaplig tidskrift, 2010
"Water In Star-forming regions with Herschel" (WISH) is a key programme dedicated to studying the role of water and related species during the star-formation process and constraining the physical and chemical properties of young stellar objects. The Heterodyne Instrument for the Far-Infrared (HIFI) on the Herschel Space Observatory observed three deeply embedded protostars in the low-mass star-forming region NGC 1333 in several H216O, H218O, and CO transitions. Line profiles are resolved for five H216O transitions in each source, revealing them to be surprisingly complex. The line profiles are decomposed into broad (>20 kms-1), medium-broad (~5-10 kms-1), and narrow (<5 kms-1) components. The H218O emission is only detected in broad 110-101 lines (>20 kms-1), indicating that its physical origin is the same as for the broad H216O component. In one of the sources, IRAS4A, an inverse P Cygni profile is observed, a clear sign of infall in the envelope. From the line profiles alone, it is clear that the bulk of emission arises from shocks, both on small (\lap1000 AU) and large scales along the outflow cavity walls (~10 000 AU). The H2O line profiles are compared to CO line profiles to constrain the H2O abundance as a function of velocity within these shocked regions. The H2O/CO abundance ratios are measured to be in the range of ~0.1-1, corresponding to H2O abundances of ~10-5-10-4 with respect to H2. Approximately 5-10% of the gas is hot enough for all oxygen to be driven into water in warm post-shock gas, mostly at high velocities.
astrochemistry
stars: formation
ISM: jets and outflows
ISM: molecules
ISM: individual objects: NGC 1333
Författare
L. Kristensen
Universiteit Leiden
R. Visser
Universiteit Leiden
E. F. van Dishoeck
Max-Planck-Gesellschaft
Universiteit Leiden
U. A. Yildiz
Universiteit Leiden
S. Doty
Denison University
G. J. Herczeg
Max-Planck-Gesellschaft
F.-C. Liu
Max-Planck-Gesellschaft
B. Parise
Max-Planck-Gesellschaft
J. K. Jorgensen
Köpenhamns universitet
T. A. van Kempen
Harvard-Smithsonian Center for Astrophysics
C. Brinch
Universiteit Leiden
S. F. Wampfler
Eidgenössische Technische Hochschule Zürich (ETH)
S. Bruderer
Eidgenössische Technische Hochschule Zürich (ETH)
A. O. Benz
Eidgenössische Technische Hochschule Zürich (ETH)
M. R. Hogerheijde
Universiteit Leiden
E. Deul
Universiteit Leiden
R. Bachiller
Observatorio Astronómico Nacional (OAN)
A. Baudry
Laboratoire d'Astrophysique de Bordeaux
M. Benedettini
Istituto di Fisica dello Spazio Interplanetario, Rome
E. A. Bergin
University of Michigan
Per Bjerkeli
Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik
G. A. Blake
California Institute of Technology (Caltech)
S. Bontemps
Laboratoire d'Astrophysique de Bordeaux
J. Braine
Laboratoire d'Astrophysique de Bordeaux
P. Caselli
University of Leeds
Osservatorio Astrofisico di Arcetri
J. Cernicharo
Centro de Astrobiologia (CAB)
C. Codella
Osservatorio Astrofisico di Arcetri
F. Daniel
Centro de Astrobiologia (CAB)
T. de Graauw
Netherlands Institute for Space Research (SRON)
A. M. di Giorgio
Istituto di Fisica dello Spazio Interplanetario, Rome
C. Dominik
Anton Pannekoek Institute for Astronomy
Radboud Universiteit
P. Encrenaz
LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres
M. Fich
University of Waterloo
A. Fuente
Observatorio Astronómico Nacional (OAN)
T. Giannini
Osservatorio Astronomico di Roma
J. R. Goicoechea
Centro de Astrobiologia (CAB)
F. Helmich
Netherlands Institute for Space Research (SRON)
F. Herpin
Laboratoire d'Astrophysique de Bordeaux
T. Jacq
Laboratoire d'Astrophysique de Bordeaux
D. Johnstone
University of Victoria
National Research Council Canada
M. J. Kaufman
San Jose State University
B. Larsson
Stockholms universitet
D. Lis
California Institute of Technology (Caltech)
René Liseau
Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik
M. Marseille
Netherlands Institute for Space Research (SRON)
C. McCoey
University of Waterloo
Western University
G. J. Melnick
Harvard-Smithsonian Center for Astrophysics
D. A. Neufeld
Johns Hopkins University
B. Nisini
Osservatorio Astronomico di Roma
Michael Olberg
Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium
J. C. Pearson
Jet Propulsion Laboratory, California Institute of Technology
R. Plume
University of Calgary
C. Risacher
Netherlands Institute for Space Research (SRON)
J. Santiago-García
Institut de Radioastronomie Millimétrique (IRAM)
P. Saraceno
Istituto di Fisica dello Spazio Interplanetario, Rome
R. Shipman
Netherlands Institute for Space Research (SRON)
M. Tafalla
Observatorio Astronómico Nacional (OAN)
Aggm Tielens
Universiteit Leiden
F. F. S. van der Tak
Netherlands Institute for Space Research (SRON)
Rijksuniversiteit Groningen
F. Wyrowski
Max-Planck-Gesellschaft
D. Beintema
Netherlands Institute for Space Research (SRON)
A. de Jonge
Netherlands Institute for Space Research (SRON)
P. Dieleman
Netherlands Institute for Space Research (SRON)
V. Ossenkopf
Universität zu Köln
P. Roelfsema
Netherlands Institute for Space Research (SRON)
J. Stutzki
Universität zu Köln
N. Whyborn
Atacama Large Millimeter-submillimeter Array (ALMA)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 521 1 Art. Nr. L30- L30Ämneskategorier
Astronomi, astrofysik och kosmologi
Fundament
Grundläggande vetenskaper
DOI
10.1051/0004-6361/201015100