On the central abundances of Active Galactic Nuclei and Star-forming Galaxies
We examine the relation between oxygen abundances in the narrow-line regions (NLRs) of active galactic nuclei (AGNs) estimated from the optical emission lines through the strong-line method (the theoretical calibration of Storchi-Bergmann et al. 1998), via the direct Te-method, and the central inter...
| Autores: | , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Argentina |
| Recursos: | Universidad Nacional de La Plata |
| Repositorio: | SEDICI (UNLP) |
| Idioma: | inglés |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/93847 |
| Acesso em linha: | http://sedici.unlp.edu.ar/handle/10915/93847 |
| Access Level: | acceso abierto |
| Palavra-chave: | Astronomía Física Ciencias Naturales Ciencias Exactas Evolution of galaxies Abundances Formation of galaxies Interstellar medium |
| Resumo: | We examine the relation between oxygen abundances in the narrow-line regions (NLRs) of active galactic nuclei (AGNs) estimated from the optical emission lines through the strong-line method (the theoretical calibration of Storchi-Bergmann et al. 1998), via the direct Te-method, and the central intersect abundances in the host galaxies determined from the radial abundance gradients. We found that the T<sub>e</sub>-method underestimates the oxygen abundances by up to ∼2 dex (with average value of ~0.8 dex) compared to the abundances derived through the strong-line method. This con- firms the existence of the so-called ?temperature problem? in AGNs. We also found that the abundances in the centres of galaxies obtained from their spectra trough the strong-line method are close to or slightly lower than the central intersect abun- dances estimated from the radial abundance gradient both in AGNs and Star-forming galaxies. The oxygen abundance of the NLR is usually lower than the maximum at- tainable abundance in galaxies (~2 times the solar value). This suggests that there is no extraordinary chemical enrichment of the NLRs of AGNs. |
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