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: individual objects: NGC 1333

ISM: molecules

ISM: jets and outflows

Författare

L. Kristensen

Leiden University

R. Visser

Leiden University

E. F. van Dishoeck

Max Planck-institutet

Leiden University

U. A. Yildiz

Leiden University

S. Doty

Denison University

G. J. Herczeg

Max Planck-institutet

F.-C. Liu

Max Planck-institutet

B. Parise

Max Planck-institutet

J. K. Jorgensen

Kobenhavns Universitet

T. A. van Kempen

Harvard-Smithsonian Center for Astrophysics

C. Brinch

Leiden University

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

Leiden University

E. Deul

Leiden University

R. Bachiller

Observatorio Astronomico Nacional

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

Caltech Division of Geological and Planetary Sciences

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

CSIC-INTA - Centro de Astrobiologia (CAB)

C. Codella

Osservatorio Astrofisico di Arcetri

F. Daniel

CSIC-INTA - Centro de Astrobiologia (CAB)

T. de Graauw

SRON Netherlands Institute for Space Research

A. M. di Giorgio

Istituto di Fisica dello Spazio Interplanetario, Rome

C. Dominik

Astronomical Institute Anton Pannekoek

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 Astronomico Nacional

T. Giannini

Osservatorio Astronomico di Roma

J. R. Goicoechea

CSIC-INTA - Centro de Astrobiologia (CAB)

F. Helmich

SRON Netherlands Institute for Space Research

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

CalTech

René Liseau

Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik

M. Marseille

SRON Netherlands Institute for Space Research

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

SRON Netherlands Institute for Space Research

J. Santiago-García

Instituto de Radioastronomia Milimetrica

P. Saraceno

Istituto di Fisica dello Spazio Interplanetario, Rome

R. Shipman

SRON Netherlands Institute for Space Research

M. Tafalla

Observatorio Astronomico Nacional

Aggm Tielens

Leiden University

F. F. S. van der Tak

University of Groningen, Kapteyn Astronomical Institute

SRON Netherlands Institute for Space Research

F. Wyrowski

Max Planck-institutet

D. Beintema

SRON Netherlands Institute for Space Research

A. de Jonge

SRON Netherlands Institute for Space Research

P. Dieleman

SRON Netherlands Institute for Space Research

V. Ossenkopf

Universität zu Köln

P. Roelfsema

SRON Netherlands Institute for Space Research

J. Stutzki

Universität zu Köln

N. Whyborn

Atacama Large Millimeter-submillimeter Array

Astronomy and Astrophysics

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

Vol. 521 Art. Nr. L30- L30

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1051/0004-6361/201015100