Herschel/HIFI detections of hydrides towards AFGL 2591 Envelope emission versus tenuous cloud absorption
Artikel i vetenskaplig tidskrift, 2010
The Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory allows the first observations of light diatomic molecules at high spectral resolution and in multiple transitions. Here, we report deep integrations using HIFI in different lines of hydrides towards the high-mass star forming region AFGL 2591. Detected are CH, CH+, NH, OH+, H2O+, while NH+ and SH+ have not been detected. All molecules except for CH and CH+ are seen in absorption with low excitation temperatures and at velocities different from the systemic velocity of the protostellar envelope. Surprisingly, the CH(J(F,P) = 3/2(2),(-) - 1/2(1,+)) and CH+(J = 1-0, J = 2-1) lines are detected in emission at the systemic velocity. We can assign the absorption features to a foreground cloud and an outflow lobe, while the CH and CH+ emission stems from the envelope. The observed abundance and excitation of CH and CH+ can be explained in the scenario of FUV irradiated outflow walls, where a cavity etched out by the outflow allows protostellar FUV photons to irradiate and heat the envelope at larger distances driving the chemical reactions that produce these molecules.
ISM: individual objects: AFGL 2591
astrochemistry
ISM: molecules
stars: formation
Författare
S. Bruderer
Eidgenössische Technische Hochschule Zürich (ETH)
A. O. Benz
Fachhochschule Nordwestschweiz
E. F. van Dishoeck
Universiteit Leiden
M. Melchior
Fachhochschule Nordwestschweiz
S. Doty
Denison University
F. F. S. van der Tak
Rijksuniversiteit Groningen
P. Stauber
Eidgenössische Technische Hochschule Zürich (ETH)
S. F. Wampfler
Universität Bern
C. Dedes
Eidgenössische Technische Hochschule Zürich (ETH)
U. A. Yildiz
California Institute of Technology (Caltech)
L. Pagani
Sorbonne Université
T. Giannini
Osservatorio Astronomico di Roma
T. de Graauw
Universiteit Leiden
N. Whyborn
Cherenkov Telescope Array
D. Teyssier
Europeiska rymdorganisationen (ESA)
W. Jellema
Netherlands Institute for Space Research (SRON)
R. Shipman
Netherlands Institute for Space Research (SRON)
R. Schieder
Universität zu Köln
N. Honingh
Universität zu Köln
E. Caux
Universite Paul Sabatier Toulouse III
W. Bachtold
Eidgenössische Technische Hochschule Zürich (ETH)
A. Csillaghy
Fachhochschule Nordwestschweiz
C. Monstein
Istituto Ricerche Solari Locarno
R. Bachiller
Observatorio Astronómico Nacional (OAN)
A. Baudry
Université de Bordeaux
M. Benedettini
Istituto nazionale di astrofisica (INAF)
E. A. Bergin
University of Michigan
Per Bjerkeli
Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik
G. A. Blake
California Institute of Technology (Caltech)
S. Bontemps
Université de Bordeaux
J. Braine
Université de Bordeaux
P. Caselli
Max-Planck-Gesellschaft
J. Cernicharo
Consejo Superior de Investigaciones Científicas (CSIC)
C. Codella
Osservatorio Astrofisico di Arcetri
F. Daniel
Université Grenoble Alpes
A. M. di Giorgio
Istituto nazionale di astrofisica (INAF)
C. Dominik
Sterrenkundig Instituut Anton Pannekoek
P. Encrenaz
Observatoire de Paris
M. Fich
University of Waterloo
A. Fuente
Observatorio Astronómico Nacional (OAN)
J. R. Goicoechea
Consejo Superior de Investigaciones Científicas (CSIC)
F. Helmich
Rijksuniversiteit Groningen
G. J. Herczeg
Peking University
F. Herpin
Université de Bordeaux
M. R. Hogerheijde
Universiteit Van Amsterdam
T. Jacq
Université de Bordeaux
D. Johnstone
University of Victoria
J. K. Jorgensen
Köpenhamns universitet
L. Kristensen
Niels Bohr Institute
B. Larsson
Stockholms universitet
D. Lis
California Institute of Technology (Caltech)
René Liseau
Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik
M. Marseille
Centre National d'Etudes Spatiales (CNES)
C. McCoey
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, Rymd- och geovetenskap, Onsala rymdobservatorium
B. Parise
Max-Planck-Gesellschaft
J. C. Pearson
California Institute of Technology (Caltech)
R. Plume
University of Calgary
C. Risacher
Institut de Radioastronomie Millimétrique (IRAM)
J. Santiago-García
Instituto de Radioastronomía Milimétrica
P. Saraceno
Istituto nazionale di astrofisica (INAF)
M. Tafalla
Observatorio Astronómico Nacional (OAN)
T. A. van Kempen
Netherlands Institute for Space Research (SRON)
R. Visser
European Southern Observatory (ESO)
F. Wyrowski
Max-Planck-Gesellschaft
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 521 1 L44Ämneskategorier (SSIF 2011)
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/201015098