FITTING PHOTOIONIZATION MODELS TO PLANETARY NEBULAE
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| Natura: | Artículo científico |
| Lingua: | en |
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Universidad Nacional Autónoma de México
2009
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| _version_ | 1876445775997698048 |
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| author | J. Bohigas |
| author_facet | J. Bohigas |
| contents | FITTING PHOTOIONIZATION MODELS TO PLANETARY NEBULAE J. Bohigas Física, Astronomía y Matemáticas AGB ISM: abundances planetary nebulae methods: numerical stars: AGB and post Good to excellent photoionization models based on the Cloudy code were obtained for 13 out of 19 spectra of planetary nebulae. The two most important assumptions are that the photoionizing continuum is a Rauch model star, with gravity set by the condition that the stellar mass must be 1 M, and density is constant and determined from the observed [S II]6717/6731 ratio. The temperature and luminosity of the central star, the inner radius of the nebula and the abundance of carbon are treated as free parameters in each model run, destined to obtain the best possible t to the relative intensities of He II 4686, [O III]5007 and [N II]6584. Observed and modeled nebular temperatures derived from [N II] (6548+6584) /5755 agree within 10%, but models usually underestimate temperatures found from [O III] (4959+5007) /4363, more so when the slit does not cover the in-depth extent of the ionized region. Helium, nitrogen, oxygen, neon, sulfur and argon model abundances are uncertain at the 15%, 15%, 10%, 7%, 30% and 7% level. It is shown that neon abundance in PNe has been consistently overestimated, and an alternative ionization correction factor is recommended. 2009 artículo científico 0185-1101 https://www.redalyc.org/articulo.oa?id=57115758016 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.35 |
| format | Artículo científico |
| id | redalyc_57115758016 |
| institution | Redalyc |
| language | en |
| publishDate | 2009 |
| publisher | Universidad Nacional Autónoma de México |
| spellingShingle | FITTING PHOTOIONIZATION MODELS TO PLANETARY NEBULAE J. Bohigas Física, Astronomía y Matemáticas AGB ISM: abundances planetary nebulae methods: numerical stars: AGB and post FITTING PHOTOIONIZATION MODELS TO PLANETARY NEBULAE J. Bohigas Física, Astronomía y Matemáticas AGB ISM: abundances planetary nebulae methods: numerical stars: AGB and post Good to excellent photoionization models based on the Cloudy code were obtained for 13 out of 19 spectra of planetary nebulae. The two most important assumptions are that the photoionizing continuum is a Rauch model star, with gravity set by the condition that the stellar mass must be 1 M, and density is constant and determined from the observed [S II]6717/6731 ratio. The temperature and luminosity of the central star, the inner radius of the nebula and the abundance of carbon are treated as free parameters in each model run, destined to obtain the best possible t to the relative intensities of He II 4686, [O III]5007 and [N II]6584. Observed and modeled nebular temperatures derived from [N II] (6548+6584) /5755 agree within 10%, but models usually underestimate temperatures found from [O III] (4959+5007) /4363, more so when the slit does not cover the in-depth extent of the ionized region. Helium, nitrogen, oxygen, neon, sulfur and argon model abundances are uncertain at the 15%, 15%, 10%, 7%, 30% and 7% level. It is shown that neon abundance in PNe has been consistently overestimated, and an alternative ionization correction factor is recommended. 2009 artículo científico 0185-1101 https://www.redalyc.org/articulo.oa?id=57115758016 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.35 |
| title | FITTING PHOTOIONIZATION MODELS TO PLANETARY NEBULAE |
| topic | Física, Astronomía y Matemáticas AGB ISM: abundances planetary nebulae methods: numerical stars: AGB and post |
| url | https://www.redalyc.org/articulo.oa?id=57115758016 |