Variations in H2O+/H2O ratios toward massive star-forming regions
Artikel i vetenskaplig tidskrift, 2010

Early results from the Herschel Space Observatory revealed the water cation H2O+ to be an abundant ingredient of the interstellar medium. Here we present new observations of the H2O and H2O+ lines at 1113.3 and 1115.2 GHz using the Herschel Space Observatory toward a sample of high-mass star-forming regions to observationally study the relation between H2O and H2O+. Nine out of ten sources show absorption from H2O+ in a range of environments: the molecular clumps surrounding the forming and newly formed massive stars, bright high-velocity outflows associated with the massive protostars, and unrelated low-density clouds along the line of sight. Column densities per velocity component of H2O+ are found in the range of 10^12 to a few 10^13 cm^-2. The highest N(H2O+) column densities are found in the outflows of the sources. The ratios of H2O+/H2O are determined in a range from 0.01 to a few and are found to differ strongly between the observed environments with much lower ratios in the massive (proto)cluster envelopes (0.01-0.1) than in outflows and diffuse clouds. Remarkably, even for source components detected in H2O in emission, H2O+ is still seen in absorption. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

ISM: clouds

stars: formation

submillimeter: ISM

ISM: molecules

Författare

F. Wyrowski

Max Planck-institutet

F. F. S. van der Tak

Netherlands Institute for Space Research (SRON)

Rijksuniversiteit Groningen

F. Herpin

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

S. Bontemps

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

L. Chavarría

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

W. Frieswijk

Rijksuniversiteit Groningen

T. Jacq

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

M. Marseille

Netherlands Institute for Space Research (SRON)

R. Shipman

Netherlands Institute for Space Research (SRON)

E. F. van Dishoeck

Max Planck-institutet

Universiteit Leiden

A. O. Benz

Eidgenössische Technische Hochschule Zürich (ETH)

P. Caselli

University of Leeds

M. R. Hogerheijde

Universiteit Leiden

D. Johnstone

National Research Council Canada

University of Victoria

René Liseau

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

R. Bachiller

Observatorio Astronomico Nacional

M. Benedettini

Universita degli Studi di Roma Tor Vergata

University of Michigan

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

J. Braine

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

S. Bruderer

Eidgenössische Technische Hochschule Zürich (ETH)

J. Cernicharo

CSIC-INTA - Centro de Astrobiologia (CAB)

C. Codella

Universita degli Studi di Roma Tor Vergata

F. Daniel

Consejo Superior de Investigaciones Científicas

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

A. M. di Giorgio

Universita degli Studi di Roma Tor Vergata

C. Dominik

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 Astronomico Nacional

T. Giannini

Universita degli Studi di Roma Tor Vergata

J. R. Goicoechea

CSIC-INTA - Centro de Astrobiologia (CAB)

T. de Graauw

Atacama Large Millimeter-submillimeter Array (ALMA)

F. Helmich

Netherlands Institute for Space Research (SRON)

G. J. Herczeg

Max Planck-institutet

J. K. Jorgensen

Köbenhavns Universitet

L. Kristensen

Universiteit Leiden

B. Larsson

Stockholms universitet

D. Lis

Caltech Division of Geological and Planetary Sciences

C. McCoey

University of Waterloo

G. J. Melnick

Harvard-Smithsonian Center for Astrophysics

B. Nisini

Universita degli Studi di Roma Tor Vergata

Michael Olberg

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

B. Parise

Max Planck-institutet

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

Observatorio Astronomico Nacional

P. Saraceno

Universita degli Studi di Roma Tor Vergata

M. Tafalla

Observatorio Astronomico Nacional

T. A. van Kempen

Harvard-Smithsonian Center for Astrophysics

R. Visser

Universiteit Leiden

S. F. Wampfler

Eidgenössische Technische Hochschule Zürich (ETH)

U. A. Yildiz

Universiteit Leiden

John H Black

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

E. Falgarone

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

M. Gerin

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

P. Roelfsema

Netherlands Institute for Space Research (SRON)

P. Dieleman

Netherlands Institute for Space Research (SRON)

D. Beintema

Netherlands Institute for Space Research (SRON)

A. de Jonge

Netherlands Institute for Space Research (SRON)

N. Whyborn

Atacama Large Millimeter-submillimeter Array (ALMA)

J. Stutzki

Universität zu Köln

V. Ossenkopf

Universität zu Köln

Astronomy and Astrophysics

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

Vol. 521 L34+- L34

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1051/0004-6361/201015110