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| Formato: | Artículo científico |
| Lenguaje: | en |
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Universidad Nacional Autónoma de México
2001
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| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=57101006 |
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- The o II recombination line abundance problem in planetary nebulae H. L. Dinerstein D. R. Garnett Física, Astronomía y Matemáticas ISM: INDIVIDUAL: RING NEBULA PLANETARY NEBULAE: ABUNDANCES We present new observations of O II recombination lines in ten bright plane-tary nebulae, along with spatially-resolved measurements of O II and [O III] in theRing nebula NGC 6720, to study the discrepancy between abundances derived fromO II recombination lines and those derived from collisionally-excited [O III]. We seea large range in the di erence between O II- and [O III] derived abundances, from nodi erence up to a factor six di erence. The size of this discrepancy is anti-correlatedwith nebular surface brightness; compact, high-surface-brightness nebulae have thesmallest discrepancies. O II levels that are populated mainly by dielectronic recom-bination give larger abundances than other levels. Finally, our long-slit observationof the Ring nebula shows that the O II emission peaks interior to the bright shellwhere [O III] and H are strongest. Based on the observed correlations, we pro-pose that the strong recombination line emission in planetary nebulae is a resultof enhanced dielectronic recombination in hot gas in the nebular interior, perhapsdriven by a hot stellar wind. 2001 artículo científico 0185-1101 https://www.redalyc.org/articulo.oa?id=57101006 en http://www.redalyc.org/revista.oa?id=571 Revista Mexicana de Astronomía y Astrofísica application/pdf Universidad Nacional Autónoma de México Revista Mexicana de Astronomía y Astrofísica (México) Vol.10