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.


I. Aleman

Leiden Observatory Research Institute

T. Ueta

University of Denver

JAXA Institute of Space and Astronautical Science

D. Ladjal

University of Denver

K. M. Exter

KU Leuven

J. H. Kastner

Rochester Institute of Technology

R. Montez

Vanderbilt University

Aggm Tielens

Leiden Observatory Research Institute

Y. H. Chu

University of Illinois

H. Izumiura

National Institutes of Natural Sciences - National Astronomical Observatory of Japan

I. McDonald

University of Manchester

R. Sahai

Jet Propulsion Laboratory, California Institute of Technology

N. Siodmiak

Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences

R. Szczerba

Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences

P. A. M. van Hoof

Royal Observatory of Belgium

E. Villaver

Universidad Autonoma de Madrid

Wouter Vlemmings

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

M. Wittkowski

European Southern Observatory

A. Zijlstra

University of Manchester

Astronomy and Astrophysics

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

Vol. 566 A79


Astronomi, astrofysik och kosmologi