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dc.contributor.authorBinette, Lucpt_BR
dc.contributor.authorWilson, Andrew S.pt_BR
dc.contributor.authorRaga, Alexpt_BR
dc.contributor.authorStorchi-Bergmann, Thaisapt_BR
dc.date.accessioned2014-07-23T02:04:40Zpt_BR
dc.date.issued1997pt_BR
dc.identifier.issn0004-6361pt_BR
dc.identifier.urihttp://hdl.handle.net/10183/98392pt_BR
dc.description.abstractRecent 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.en
dc.format.mimetypeapplication/pdf
dc.language.isoengpt_BR
dc.relation.ispartofAstronomy and Astrophysics. Berlin. Vol. 327, no. 3 (Nov. 1997), p. 909-920pt_BR
dc.rightsOpen Accessen
dc.subjectAstrofisica extragalaticapt_BR
dc.subjectGalaxies: activeen
dc.subjectFormacao de galaxiaspt_BR
dc.subjectGalaxies: Seyferten
dc.subjectGalaxias seyfertpt_BR
dc.subjectLine: formationen
dc.subjectGalaxies: ISMen
dc.subjectFotoionizacaopt_BR
dc.subjectNucleo galaticopt_BR
dc.subjectGalaxies: Circinus galaxyen
dc.titlePhotoionization of very high excitation gas in circinus galaxy and other active galactic nucleipt_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb000152525pt_BR
dc.type.originEstrangeiropt_BR


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