Herschel Planetary Nebula Survey (HerPlaNS) First detection of OH+ in planetary nebulae
Artikel i vetenskaplig tidskrift, 2014
Aims. We report the first detections of OH+ emission in planetary nebulae (PNe). Methods. As part of an imaging and spectroscopy survey of 11 PNe in the far-IR using the PACS and SPIRE instruments aboard the Herschel Space Observatory, we performed a line survey in these PNe over the entire spectral range between 51 mu m and 672 mu m to look for new detections. Results. The rotational emission lines of OH+ at 152.99, 290.20, 308.48, and 329.77 mu m were detected in the spectra of three planetary nebulae: NGC 6445, NGC6720, and NGC 6781. Excitation temperatures and column densities derived from these lines are in the range of 27-47 K and 2 x 10(10)-4 x 10(11) cm(-2), respectively. Conclusions. In PNe, the OH+ rotational line emission appears to be produced in the photodissociation region (PDR) in these objects. The emission of OH+ is observed only in PNe with hot central stars (T-eff > 100 000 K), suggesting that high-energy photons may play a role in OH+ formation and its line excitation in these objects, as seems to be the case for ultraluminous galaxies.
Författare
I. Aleman
Universiteit Leiden
T. Ueta
JAXA Institute of Space and Astronautical Science
University of Denver
D. Ladjal
University of Denver
K. M. Exter
KU Leuven
J. H. Kastner
Rochester Institute of Technology
R. Montez
Vanderbilt University
Aggm Tielens
Universiteit Leiden
Y. H. Chu
University of Illinois
H. Izumiura
National Astronomical Observatory of Japan
I. McDonald
University of Manchester
R. Sahai
Jet Propulsion Laboratory, California Institute of Technology
N. Siodmiak
Polish Academy of Sciences
R. Szczerba
Polish Academy of Sciences
P. A. M. van Hoof
Royal Observatory of Belgium
E. Villaver
Universidad Autonoma de Madrid (UAM)
Wouter Vlemmings
Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium
M. Wittkowski
European Southern Observatory (ESO)
A. Zijlstra
University of Manchester
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 566 A79Ämneskategorier
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/201322940