Herschel Planetary Nebula Survey (HerPlaNS): First detection of OH + in planetary nebulae

I. Aleman, T. Ueta, D. Ladjal, K. M. Exter, J. H. Kastner, R. Montez, A. G G M Tielens, Y. H. Chu, H. Izumiura, I. McDonald, R. Sahai, N. Siódmiak, R. Szczerba, P. A M Van Hoof, E. Villaver, W. Vlemmings, M. Wittkowski, A. A. Zijlstra

    Research output: Contribution to journalArticlepeer-review


    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 51μm and 672μm to look for new detections. Results. The rotational emission lines of OH+ at 152.99, 290.20, 308.48, and 329.77μm were detected in the spectra of three planetary nebulae: NGC 6445, NGC 6720, and NGC 6781. Excitation temperatures and column densities derived from these lines are in the range of 27-47 K and 2 × 1010-4 × 1011 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 (Teff> 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. © ESO, 2014.
    Original languageEnglish
    Article numberA79
    JournalAstronomy and Astrophysics
    Publication statusPublished - 2014


    • Astrochemistry
    • Circumstellar matter
    • Planetary nebulae: general
    • Planetary nebulae: individual: NGC 6445
    • Planetary nebulae: individual: NGC 6720
    • Planetary nebulae: individual: NGC 6781


    Dive into the research topics of 'Herschel Planetary Nebula Survey (HerPlaNS): First detection of OH + in planetary nebulae'. Together they form a unique fingerprint.

    Cite this