The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies
Autor(a) principal: | |
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Data de Publicação: | 1998 |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/108773 |
Resumo: | This paper presents a comparative study of emission-line ratios of the narrow-line regions (NLRs) of Seyfert 1 and Seyfert 2 galaxies. It includes a literature compilation of the emission-line fluxes [O II] λ3727, [Ne III] λ3869, [O III] λ5007, and [Ne V] λ3426 as well as 60 μm continuum flux, for a sample of 52 Seyfert 1 and 68 Seyfert 2 galaxies. The distribution of the emission-line ratios [O II]/[Ne III] and [O II]/[Ne V] shows that Seyfert 1 and Seyfert 2 galaxies are statistically different : Seyfert 1 galaxies have smaller values than Seyfert 2 galaxies, indicating a higher excitation spectrum. These and other emission-line ratios are compared with sequences of models that combine different proportions of matter and ionization-bounded clouds and also with sequences of models that vary only the ionization parameter. This comparison shows that the former models better reproduce the overall distribution of emission-line ratios, indicating that Seyfert 1 galaxies have a smaller number of ionization-bounded clouds than Seyfert 2 galaxies. This difference, together with other results available in the literature, are interpreted from the point of view of four different scenarios. The most likely scenario assumes that Seyfert 1 galaxies have smaller NLRs than Seyfert 2 galaxies, possibly due to a preferential alignment of the torus axis close to the host galaxy plane axis in Seyfert 1 galaxies. |
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Schmitt, Henrique Roberto2015-01-07T02:10:39Z19980004-637Xhttp://hdl.handle.net/10183/108773000198880This paper presents a comparative study of emission-line ratios of the narrow-line regions (NLRs) of Seyfert 1 and Seyfert 2 galaxies. It includes a literature compilation of the emission-line fluxes [O II] λ3727, [Ne III] λ3869, [O III] λ5007, and [Ne V] λ3426 as well as 60 μm continuum flux, for a sample of 52 Seyfert 1 and 68 Seyfert 2 galaxies. The distribution of the emission-line ratios [O II]/[Ne III] and [O II]/[Ne V] shows that Seyfert 1 and Seyfert 2 galaxies are statistically different : Seyfert 1 galaxies have smaller values than Seyfert 2 galaxies, indicating a higher excitation spectrum. These and other emission-line ratios are compared with sequences of models that combine different proportions of matter and ionization-bounded clouds and also with sequences of models that vary only the ionization parameter. This comparison shows that the former models better reproduce the overall distribution of emission-line ratios, indicating that Seyfert 1 galaxies have a smaller number of ionization-bounded clouds than Seyfert 2 galaxies. This difference, together with other results available in the literature, are interpreted from the point of view of four different scenarios. The most likely scenario assumes that Seyfert 1 galaxies have smaller NLRs than Seyfert 2 galaxies, possibly due to a preferential alignment of the torus axis close to the host galaxy plane axis in Seyfert 1 galaxies.application/pdfengThe Astrophysical journal. Chicago. Vol. 506, no. 2, pt. 1 (Oct. 1998), p. 647-657Materia interestelarGalaxias seyfertEspectros astronômicosRadioastronomiaNucleo galaticoGalaxies : seyfertGalaxies : activeGalaxies : nucleiThe difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxiesEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSORIGINAL000198880.pdf000198880.pdfTexto completo (inglês)application/pdf181119http://www.lume.ufrgs.br/bitstream/10183/108773/1/000198880.pdf7712823776d2d541bef6ad66fbed97eeMD51TEXT000198880.pdf.txt000198880.pdf.txtExtracted Texttext/plain55562http://www.lume.ufrgs.br/bitstream/10183/108773/2/000198880.pdf.txt3991dcc28952b32f2a598637718f1a51MD52THUMBNAIL000198880.pdf.jpg000198880.pdf.jpgGenerated Thumbnailimage/jpeg2242http://www.lume.ufrgs.br/bitstream/10183/108773/3/000198880.pdf.jpg3988feb35bc07b68b130585a3a468ed0MD5310183/1087732018-10-23 08:34:32.888oai:www.lume.ufrgs.br:10183/108773Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2018-10-23T11:34:32Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies |
title |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies |
spellingShingle |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies Schmitt, Henrique Roberto Materia interestelar Galaxias seyfert Espectros astronômicos Radioastronomia Nucleo galatico Galaxies : seyfert Galaxies : active Galaxies : nuclei |
title_short |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies |
title_full |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies |
title_fullStr |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies |
title_full_unstemmed |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies |
title_sort |
The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies |
author |
Schmitt, Henrique Roberto |
author_facet |
Schmitt, Henrique Roberto |
author_role |
author |
dc.contributor.author.fl_str_mv |
Schmitt, Henrique Roberto |
dc.subject.por.fl_str_mv |
Materia interestelar Galaxias seyfert Espectros astronômicos Radioastronomia Nucleo galatico |
topic |
Materia interestelar Galaxias seyfert Espectros astronômicos Radioastronomia Nucleo galatico Galaxies : seyfert Galaxies : active Galaxies : nuclei |
dc.subject.eng.fl_str_mv |
Galaxies : seyfert Galaxies : active Galaxies : nuclei |
description |
This paper presents a comparative study of emission-line ratios of the narrow-line regions (NLRs) of Seyfert 1 and Seyfert 2 galaxies. It includes a literature compilation of the emission-line fluxes [O II] λ3727, [Ne III] λ3869, [O III] λ5007, and [Ne V] λ3426 as well as 60 μm continuum flux, for a sample of 52 Seyfert 1 and 68 Seyfert 2 galaxies. The distribution of the emission-line ratios [O II]/[Ne III] and [O II]/[Ne V] shows that Seyfert 1 and Seyfert 2 galaxies are statistically different : Seyfert 1 galaxies have smaller values than Seyfert 2 galaxies, indicating a higher excitation spectrum. These and other emission-line ratios are compared with sequences of models that combine different proportions of matter and ionization-bounded clouds and also with sequences of models that vary only the ionization parameter. This comparison shows that the former models better reproduce the overall distribution of emission-line ratios, indicating that Seyfert 1 galaxies have a smaller number of ionization-bounded clouds than Seyfert 2 galaxies. This difference, together with other results available in the literature, are interpreted from the point of view of four different scenarios. The most likely scenario assumes that Seyfert 1 galaxies have smaller NLRs than Seyfert 2 galaxies, possibly due to a preferential alignment of the torus axis close to the host galaxy plane axis in Seyfert 1 galaxies. |
publishDate |
1998 |
dc.date.issued.fl_str_mv |
1998 |
dc.date.accessioned.fl_str_mv |
2015-01-07T02:10:39Z |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
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publishedVersion |
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http://hdl.handle.net/10183/108773 |
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0004-637X |
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000198880 |
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0004-637X 000198880 |
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http://hdl.handle.net/10183/108773 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
The Astrophysical journal. Chicago. Vol. 506, no. 2, pt. 1 (Oct. 1998), p. 647-657 |
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info:eu-repo/semantics/openAccess |
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openAccess |
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application/pdf |
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