Water in massive star-forming regions: HIFI observations of W3 IRS5
Artikel i vetenskaplig tidskrift, 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.

Författare

L. Chavarría

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

F. Herpin

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

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

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

A. Baudry

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

M. Marseille

SRON Netherlands Institute for Space Research

F. F. S. van der Tak

University of Groningen, Kapteyn Astronomical Institute

SRON Netherlands Institute for Space Research

B. Pietropaoli

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

Ecole des Mines de Nantes

F. Wyrowski

Max Planck-institutet

R. Shipman

SRON Netherlands Institute for Space Research

W. Frieswijk

SRON Netherlands Institute for Space Research

E. F. van Dishoeck

Leiden Observatory Research Institute

Max Planck-institutet

J. Cernicharo

CSIC-INTA - Centro de Astrobiologia (CAB)

R. Bachiller

Observatorio Astronomico Nacional

M. Benedettini

Istituto di Fisica dello Spazio Interplanetario, Rome

A. O. Benz

ETH Zurich

E. A. Bergin

University Michigan Ann Arbor

Per Bjerkeli

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

G. A. Blake

Caltech Division of Geological and Planetary Sciences

S. Bruderer

ETH Zurich

P. Caselli

Osservatorio Astrofisico Di Arcetri

University of Leeds

C. Codella

Osservatorio Astrofisico Di Arcetri

F. Daniel

CSIC-INTA - Centro de Astrobiologia (CAB)

A. M. di Giorgio

Istituto di Fisica dello Spazio Interplanetario, Rome

C. Dominik

Astronomical Institute Anton Pannekoek

Radboud University Nijmegen

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 Astronomico Nacional

T. Giannini

Osservatorio Astronomico di Roma

J. R. Goicoechea

CSIC-INTA - Centro de Astrobiologia (CAB)

T. de Graauw

SRON Netherlands Institute for Space Research

P. Hartogh

MPI für Sonnensystemforschung

F. Helmich

SRON Netherlands Institute for Space Research

G. J. Herczeg

Max Planck-institutet

M. R. Hogerheijde

Leiden Observatory Research Institute

D. Johnstone

University of Victoria

National Research Council Canada

J. K. Jorgensen

Kobenhavns Universitet

L. Kristensen

Leiden Observatory Research Institute

B. Larsson

Stockholms universitet

D. Lis

California Institute of Technology

René Liseau

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

C. McCoey

University of Waterloo

Western University

G. J. Melnick

Harvard-Smithsonian Center for Astrophysics

B. Nisini

Osservatorio Astronomico di Roma

Michael Olberg

Chalmers, Institutionen för radio- och rymdvetenskap, Nationella anläggningen för radioastronomi

B. Parise

Max Planck-institutet

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

J. Stutzki

Universitat zu Koln

R. Szczerba

Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences

M. Tafalla

Observatorio Astronomico Nacional

A. Tielens

Leiden Observatory Research Institute

T. A. van Kempen

Harvard-Smithsonian Center for Astrophysics

R. Visser

Leiden Observatory Research Institute

S. F. Wampfler

ETH Zurich

J. Willem

SRON Netherlands Institute for Space Research

U. A. Yildiz

Leiden Observatory Research Institute

Astronomy and Astrophysics

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

Vol. 521 L37+- L37

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1051/0004-6361/201015113