Chemical abundance calibrations for the narrow-line region of active galaxies
dc.contributor.author | Storchi-Bergmann, Thaisa | pt_BR |
dc.contributor.author | Schmitt, Henrique Roberto | pt_BR |
dc.contributor.author | Calzetti, Daniela | pt_BR |
dc.contributor.author | Kinney, Anne Louise | pt_BR |
dc.date.accessioned | 2014-12-04T02:13:48Z | pt_BR |
dc.date.issued | 1998 | pt_BR |
dc.identifier.issn | 0004-6256 | pt_BR |
dc.identifier.uri | http://hdl.handle.net/10183/107739 | pt_BR |
dc.description.abstract | We investigate two chemical abundance calibrations for the narrow-line region (NLR) of active galaxies in terms of three easily observable optical emission-line ratios, namely, [O III] λλ4959, 5007/Hβ; [N II] λλ6548, 6584/Hα; and [O II] λ3727/[O III] λλ4959, 5007. The calibrations are obtained from a grid of models on the assumption that the main process responsible for the production of these lines is photoionization by a "typical" active galactic nucleus continuum. The elemental abundances vary with oxygen, except nitrogen, which is assumed to be a product of secondary nucleosynthesis. The calibrations are calculated for the range 8.4≤12]log (O/H)≤9.4 and tested using NLR data for a sample of Seyfert galaxies and LINERs that have H II regions in the vicinity of the nucleus. The gaseous abundances of these H II regions have been determined in previous works, and the NLR abundances are obtained on the assumption that they can be extrapolated from those of the H II regions. The calibrations work very well for the Seyfert galaxies, yielding abundance values that agree with those obtained from the H II regions, and can thus be used for quick estimates of the chemical abundances of the NLRs. For the LINERs, the calibrations yield lower values than those derived from the corresponding H II regions, suggesting that the assumptions of the models do not apply for them and that there are di†erent physical processes at work in the NLR of the LINERs. | en |
dc.format.mimetype | application/pdf | |
dc.language.iso | eng | pt_BR |
dc.relation.ispartof | The Astronomical journal. New York. Vol. 115, no. 3 (Mar. 1998), p. 909-914 | pt_BR |
dc.rights | Open Access | en |
dc.subject | Galaxies : active | en |
dc.subject | Astrofisica extragalatica | pt_BR |
dc.subject | Galaxies : ISM | en |
dc.subject | Nucleo galatico | pt_BR |
dc.subject | Abundancia | pt_BR |
dc.subject | Galaxies : nuclei | en |
dc.subject | Gases | pt_BR |
dc.subject | Galaxies : Seyfert | en |
dc.subject | Dinâmica | pt_BR |
dc.subject | Galaxias seyfert | pt_BR |
dc.subject | Regiões HII | pt_BR |
dc.title | Chemical abundance calibrations for the narrow-line region of active galaxies | pt_BR |
dc.type | Artigo de periódico | pt_BR |
dc.identifier.nrb | 000210688 | pt_BR |
dc.type.origin | Estrangeiro | pt_BR |
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