Galactic Bulge PNe: Carbon molecules in oxygen-rich environments
| Autor: | Tom J. Millar, Roisin Níchuimín, Eric Lagadec, Lizette Guzman-Ramirez, Paul M. Woods, Albert A. Zijlstra, Krzysztof Gesicki |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Physics
chemistry.chemical_element Astronomy Astronomy and Astrophysics Torus Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Dredge-up Planetary nebula Silicate chemistry.chemical_compound Stars chemistry Space and Planetary Science Bulge Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Low Mass Carbon Astrophysics::Galaxy Astrophysics |
| Zdroj: | Proceedings of the International Astronomical Union. 7:259-262 |
| ISSN: | 1743-9221 1743-9213 |
| DOI: | 10.1017/s1743921312011052 |
| Popis: | Galactic bulge planetary nebulae show evidence of mixed chemistry with emission from both silicate dust and PAHs. This mixed chemistry is unlikely to be related to carbon dredge up, as third dredge-up is not expected to occur in the low mass bulge stars. We show that the phenomenon is widespread, and is seen in 30 nebulae out of our sample of 40. A strong correlation is found between strength of the PAH bands and morphology, in particular, the presence of a dense torus. A chemical model is presented which shows that hydrocarbon chains can form within oxygen-rich gas through gas-phase chemical reactions. We conclude that the mixed chemistry phenomenon occurring in the galactic bulge planetary nebulae is best explained through hydrocarbon chemistry in an UV-irradiated, dense torus. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|