On the central abundances of Active Galactic Nuclei and Star-forming Galaxies
| Autor: | Dors, O. L., Cardaci, M. V., Hagele, G. F., Rodrigues, I., Grebel, E. K., Pilyugin, L. S., Freitas-Lemes, P., Krabbe, A. C. |
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| Rok vydání: | 2015 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stv1916 |
| Popis: | 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 Te-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 confirms 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 abundances 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 attainable abundance in galaxies (~2 times the solar value). This suggests that there is no extraordinary chemical enrichment of the NLRs of AGNs. Comment: Accepted in MNRAS, 11 pages, 5 figures |
| Databáze: | arXiv |
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