Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei
Autor(a) principal: | |
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Data de Publicação: | 1997 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/98392 |
Resumo: | Recent measurements of the Circinus galaxy with ISO by Moorwood et al. (1996) have confirmed the extremely high excitation of the emission-line spectrum in this active galaxy. Moorwood et al. modelled the spectrum in terms of photoionization of gas by a hard X-ray continuum plus a UV bump near 70 eV. We present new photoionization calculations which differ markedly in geometry and in the adopted spectrum of the ionizing radiation. In our model, all the zones of high excitation coexist within the internal structure of matter-bounded clouds of 1 pc thickness with a total cross section of 165 pc2. A strong UV bump is not required to explain the line ratios in this picture. Our calculations consider the effects of radiation pressure exerted by photoelectric absorption which become very important at the high ionization parameters required by the line ratios. We propose that the radiation pressure generates a strong density gradient within the photoionized structure and is responsible for accelerating the matter-bounded gas, explaining the systematic blueshift observed for the coronal lines. |
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Binette, LucWilson, Andrew S.Raga, AlexStorchi-Bergmann, Thaisa2014-07-23T02:04:40Z19970004-6361http://hdl.handle.net/10183/98392000152525Recent measurements of the Circinus galaxy with ISO by Moorwood et al. (1996) have confirmed the extremely high excitation of the emission-line spectrum in this active galaxy. Moorwood et al. modelled the spectrum in terms of photoionization of gas by a hard X-ray continuum plus a UV bump near 70 eV. We present new photoionization calculations which differ markedly in geometry and in the adopted spectrum of the ionizing radiation. In our model, all the zones of high excitation coexist within the internal structure of matter-bounded clouds of 1 pc thickness with a total cross section of 165 pc2. A strong UV bump is not required to explain the line ratios in this picture. Our calculations consider the effects of radiation pressure exerted by photoelectric absorption which become very important at the high ionization parameters required by the line ratios. We propose that the radiation pressure generates a strong density gradient within the photoionized structure and is responsible for accelerating the matter-bounded gas, explaining the systematic blueshift observed for the coronal lines.application/pdfengAstronomy and Astrophysics. Berlin. Vol. 327, no. 3 (Nov. 1997), p. 909-920Astrofisica extragalaticaFormacao de galaxiasGalaxias seyfertFotoionizacaoNucleo galaticoGalaxies: activeGalaxies: SeyfertLine: formationGalaxies: ISMGalaxies: Circinus galaxyPhotoionization of very high excitation gas in circinus galaxy and other active galactic nucleiEstrangeiroinfo: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:UFRGSORIGINAL000152525.pdf000152525.pdfTexto completo (inglês)application/pdf261768http://www.lume.ufrgs.br/bitstream/10183/98392/1/000152525.pdff83f26488579861a1685a57875c9c140MD51TEXT000152525.pdf.txt000152525.pdf.txtExtracted Texttext/plain56170http://www.lume.ufrgs.br/bitstream/10183/98392/2/000152525.pdf.txt132f1ed0b25799607e8fc79409d3b8edMD52THUMBNAIL000152525.pdf.jpg000152525.pdf.jpgGenerated Thumbnailimage/jpeg2062http://www.lume.ufrgs.br/bitstream/10183/98392/3/000152525.pdf.jpg9612d3597a720c2f87888062669f8fb2MD5310183/983922018-10-17 09:01:09.074oai:www.lume.ufrgs.br:10183/98392Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2018-10-17T12:01:09Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei |
title |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei |
spellingShingle |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei Binette, Luc Astrofisica extragalatica Formacao de galaxias Galaxias seyfert Fotoionizacao Nucleo galatico Galaxies: active Galaxies: Seyfert Line: formation Galaxies: ISM Galaxies: Circinus galaxy |
title_short |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei |
title_full |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei |
title_fullStr |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei |
title_full_unstemmed |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei |
title_sort |
Photoionization of very high excitation gas in circinus galaxy and other active galactic nuclei |
author |
Binette, Luc |
author_facet |
Binette, Luc Wilson, Andrew S. Raga, Alex Storchi-Bergmann, Thaisa |
author_role |
author |
author2 |
Wilson, Andrew S. Raga, Alex Storchi-Bergmann, Thaisa |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Binette, Luc Wilson, Andrew S. Raga, Alex Storchi-Bergmann, Thaisa |
dc.subject.por.fl_str_mv |
Astrofisica extragalatica Formacao de galaxias Galaxias seyfert Fotoionizacao Nucleo galatico |
topic |
Astrofisica extragalatica Formacao de galaxias Galaxias seyfert Fotoionizacao Nucleo galatico Galaxies: active Galaxies: Seyfert Line: formation Galaxies: ISM Galaxies: Circinus galaxy |
dc.subject.eng.fl_str_mv |
Galaxies: active Galaxies: Seyfert Line: formation Galaxies: ISM Galaxies: Circinus galaxy |
description |
Recent measurements of the Circinus galaxy with ISO by Moorwood et al. (1996) have confirmed the extremely high excitation of the emission-line spectrum in this active galaxy. Moorwood et al. modelled the spectrum in terms of photoionization of gas by a hard X-ray continuum plus a UV bump near 70 eV. We present new photoionization calculations which differ markedly in geometry and in the adopted spectrum of the ionizing radiation. In our model, all the zones of high excitation coexist within the internal structure of matter-bounded clouds of 1 pc thickness with a total cross section of 165 pc2. A strong UV bump is not required to explain the line ratios in this picture. Our calculations consider the effects of radiation pressure exerted by photoelectric absorption which become very important at the high ionization parameters required by the line ratios. We propose that the radiation pressure generates a strong density gradient within the photoionized structure and is responsible for accelerating the matter-bounded gas, explaining the systematic blueshift observed for the coronal lines. |
publishDate |
1997 |
dc.date.issued.fl_str_mv |
1997 |
dc.date.accessioned.fl_str_mv |
2014-07-23T02:04:40Z |
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 |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/98392 |
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0004-6361 |
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000152525 |
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url |
http://hdl.handle.net/10183/98392 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Astronomy and Astrophysics. Berlin. Vol. 327, no. 3 (Nov. 1997), p. 909-920 |
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info:eu-repo/semantics/openAccess |
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openAccess |
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application/pdf |
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