Hydrides in young stellar objects: Radiation tracers in a protostar-disk-outflow system
Artikel i vetenskaplig tidskrift, 2010

Context. Hydrides of the most abundant heavier elements are fundamental molecules in cosmic chemistry. Some of them trace gas irradiated by UV or X-rays. Aims: We explore the abundances of major hydrides in W3 IRS5, a prototypical region of high-mass star formation. Methods: W3 IRS5 was observed by HIFI on the Herschel Space Observatory with deep integration (\sime2500 s) in 8 spectral regions. Results: The target lines including CH, NH, H_3O^+, and the new molecules SH^+, H_2O^+, and OH^+ are detected. The H_2O^+ and OH^+ J = 1-0 lines are found mostly in absorption, but also appear to exhibit weak emission (P-Cyg-like). Emission requires high density, thus originates most likely near the protostar. This is corroborated by the absence of line shifts relative to the young stellar object (YSO). In addition, H_2O^+ and OH^+ also contain strong absorption components at a velocity shifted relative to W3 IRS5, which are attributed to foreground clouds. Conclusions: The molecular column densities derived from observations correlate well with the predictions of a model that assumes the main emission region is in outflow walls, heated and irradiated by protostellar UV radiation. Herschel is an ESA space observatory with science instruments provided by a European-led Principal Investigator consortia and with important participation from NASA.

Författare

A. O. Benz

Eidgenössische Technische Hochschule Zürich (ETH)

S. Bruderer

Eidgenössische Technische Hochschule Zürich (ETH)

E. F. van Dishoeck

Max Planck-institutet

Universiteit Leiden

P. Stäuber

Eidgenössische Technische Hochschule Zürich (ETH)

S. F. Wampfler

Eidgenössische Technische Hochschule Zürich (ETH)

M. Melchior

University of Applied Sciences Northwestern Switzerland, School of Enginnering

Eidgenössische Technische Hochschule Zürich (ETH)

C. Dedes

Eidgenössische Technische Hochschule Zürich (ETH)

F. Wyrowski

Max Planck-institutet

S. Doty

Denison University

F. F. S. van der Tak

Rijksuniversiteit Groningen

Netherlands Institute for Space Research (SRON)

W. Bächtold

Eidgenössische Technische Hochschule Zürich (ETH)

A. Csillaghy

University of Applied Sciences Northwestern Switzerland, School of Enginnering

A. Megej

Eidgenössische Technische Hochschule Zürich (ETH)

C. Monstein

Eidgenössische Technische Hochschule Zürich (ETH)

M. Soldati

University of Applied Sciences Northwestern Switzerland, School of Enginnering

R. Bachiller

Observatorio Astronamico Nacional (OAN-IGN)

A. Baudry

Laboratoire d'Astrophysique de Bordeaux

Institut National des Sciences de l'Univers

M. Benedettini

Universita degli Studi di Roma Tor Vergata

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

Institut National des Sciences de l'Univers

J. Braine

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

P. Caselli

Osservatorio Astrofisico di Arcetri

University of Leeds

J. Cernicharo

Centro de Astrobiologia (CAB)

C. Codella

Osservatorio Astrofisico di Arcetri

F. Daniel

Centro de Astrobiologia (CAB)

A. M. di Giorgio

Universita degli Studi di Roma Tor Vergata

P. Dieleman

Netherlands Institute for Space Research (SRON)

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 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)

F. Helmich

Netherlands Institute for Space Research (SRON)

G. J. Herczeg

Max Planck-institutet

F. Herpin

Institut National des Sciences de l'Univers

Laboratoire d'Astrophysique de Bordeaux

M. R. Hogerheijde

Universiteit Leiden

T. Jacq

Osservatorio Astrofisico di Arcetri

W. Jellema

Netherlands Institute for Space Research (SRON)

D. Johnstone

National Research Council Canada

University of Victoria

J. K. Jorgensen

Köbenhavns Universitet

L. Kristensen

Universiteit Leiden

B. Larsson

Stockholms universitet

D. Lis

CalTech

René Liseau

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

M. Marseille

Netherlands Institute for Space Research (SRON)

C. McCoey

Western University

University of Waterloo

G. J. Melnick

Harvard-Smithsonian Center for Astrophysics

D. A. Neufeld

Johns Hopkins University

B. Nisini

Osservatorio Astronomico di Roma

Michael Olberg

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

V. Ossenkopf

Universität zu Köln

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-García

Instituto de Radioastronomia Milimetrica

P. Saraceno

Universita degli Studi di Roma Tor Vergata

R. Schieder

Universität zu Köln

R. Shipman

Netherlands Institute for Space Research (SRON)

J. Stutzki

Universität zu Köln

M. Tafalla

Observatorio Astronamico Nacional (OAN-IGN)

Aggm Tielens

Universiteit Leiden

T. A. van Kempen

Harvard-Smithsonian Center for Astrophysics

R. Visser

Universiteit Leiden

U. A. Yildiz

Universiteit Leiden

Astronomy and Astrophysics

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

Vol. 521 1 L35+- L35

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1051/0004-6361/201015111