Water in massive star-forming regions: HIFI observations of W3 IRS5
Journal article, 2010

We present Herschel observations of the water molecule in the massive star-forming region W3 IRS5. The o-H\_2^17O 1_10-1_01, p-H\_2^18O 1_11-0_00, p-H_2O 2_02-1_11, p-H_2O 1_11-0_00, o-H_2O 2_21-2_12, and o-H_2O 2_12-1_01 lines, covering a frequency range from 552 up to 1669 GHz, have been detected at high spectral resolution with HIFI. The water lines in W3 IRS5 show well-defined high-velocity wings that indicate a clear contribution by outflows. Moreover, the systematically blue-shifted absorption in the H_2O lines suggests expansion, presumably driven by the outflow. No infall signatures are detected. The p-H_2O 1_11-0_00 and o-H_2O 2_12-1_01 lines show absorption from the cold material (T ~ 10 K) in which the high-mass protostellar envelope is embedded. One-dimensional radiative transfer models are used to estimate water abundances and to further study the kinematics of the region. We show that the emission in the rare isotopologues comes directly from the inner parts of the envelope (T \gsim 100 K) where water ices in the dust mantles evaporate and the gas-phase abundance increases. The resulting jump in the water abundance (with a constant inner abundance of 10^-4) is needed to reproduce the o-H\_2^17O 1_10-1_01 and p-H\_2^18O 1_11-0_00 spectra in our models. We estimate water abundances of 10^-8 to 10^-9 in the outer parts of the envelope (T \lsim 100 K). The possibility of two protostellar objects contributing to the emission is discussed. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Author

L. Chavarría

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

F. Herpin

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

T. Jacq

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

J. Braine

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

S. Bontemps

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

A. Baudry

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

M. Marseille

Netherlands Institute for Space Research (SRON)

F. F. S. van der Tak

Netherlands Institute for Space Research (SRON)

University of Groningen

B. Pietropaoli

Ecole des Mines de Nantes

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

F. Wyrowski

Max Planck Institute

R. Shipman

Netherlands Institute for Space Research (SRON)

W. Frieswijk

Netherlands Institute for Space Research (SRON)

E. F. van Dishoeck

Leiden University

Max Planck Institute

J. Cernicharo

Centro de Astrobiologia (CAB)

R. Bachiller

Observatorio Astronamico Nacional (OAN-IGN)

M. Benedettini

Istituto di Fisica dello Spazio Interplanetario, Rome

A. O. Benz

Swiss Federal Institute of Technology in Zürich (ETH)

E. A. Bergin

University of Michigan

Per Bjerkeli

Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics

G. A. Blake

Caltech Division of Geological and Planetary Sciences

S. Bruderer

Swiss Federal Institute of Technology in Zürich (ETH)

P. Caselli

Arcetri Astrophysical Observatory

University of Leeds

C. Codella

Arcetri Astrophysical Observatory

F. Daniel

Centro de Astrobiologia (CAB)

A. M. di Giorgio

Istituto di Fisica dello Spazio Interplanetario, Rome

C. Dominik

Radboud University

Anton Pannekoek Institute for Astronomy

S. Doty

Denison University

P. Encrenaz

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

M. Fich

University of Waterloo

A. Fuente

Observatorio Astronamico Nacional (OAN-IGN)

T. Giannini

Osservatorio Astronomico di Roma

J. R. Goicoechea

Centro de Astrobiologia (CAB)

T. de Graauw

Netherlands Institute for Space Research (SRON)

P. Hartogh

MPI für Sonnensystemforschung

F. Helmich

Netherlands Institute for Space Research (SRON)

G. J. Herczeg

Max Planck Institute

M. R. Hogerheijde

Leiden University

D. Johnstone

University of Victoria

National Research Council Canada

J. K. Jorgensen

Köbenhavns Universitet

L. Kristensen

Leiden University

B. Larsson

Stockholm University

D. Lis

CalTech

René Liseau

Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics

C. McCoey

Western University

University of Waterloo

G. J. Melnick

Harvard-Smithsonian Center for Astrophysics

B. Nisini

Osservatorio Astronomico di Roma

Michael Olberg

Chalmers, Department of Radio and Space Science, National Facility for Radio Astronomy

B. Parise

Max Planck Institute

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

Instituto de Radioastronomia Milimetrica

P. Saraceno

Istituto di Fisica dello Spazio Interplanetario, Rome

J. Stutzki

University of Cologne

R. Szczerba

Polish Academy of Sciences

M. Tafalla

Observatorio Astronamico Nacional (OAN-IGN)

A. Tielens

Leiden University

T. A. van Kempen

Harvard-Smithsonian Center for Astrophysics

R. Visser

Leiden University

S. F. Wampfler

Swiss Federal Institute of Technology in Zürich (ETH)

J. Willem

Netherlands Institute for Space Research (SRON)

U. A. Yildiz

Leiden University

Astronomy and Astrophysics

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

Vol. 521 1 L37+- L37

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

DOI

10.1051/0004-6361/201015113

More information

Latest update

10/30/2018