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dc.contributor.authorNemmen, Rodrigo S.pt_BR
dc.contributor.authorBower, Richard G.pt_BR
dc.contributor.authorBabul, Arifpt_BR
dc.contributor.authorStorchi-Bergmann, Thaisapt_BR
dc.date.accessioned2014-04-03T01:51:24Zpt_BR
dc.date.issued2007pt_BR
dc.identifier.issn0035-8711pt_BR
dc.identifier.urihttp://hdl.handle.net/10183/90264pt_BR
dc.description.abstractThe power of jets from black holes is expected to depend on both the spin of the black hole and the structure of the accretion disc in the region of the last stable orbit.We investigate these dependencies using two different physical models for the jet power: the classical Blandford– Znajek (BZ) model and a hybrid model developed by Meier. In the BZ case, the jets are powered by magnetic fields directly threading the spinning black hole while in the hybrid model, the jet energy is extracted from both the accretion disc as well as the black hole via magnetic fields anchored to the accretion flowinside and outside the hole’s ergosphere. The hybrid model takes advantage of the strengths of both the Blandford–Payne and BZ mechanisms, while avoiding the more controversial features of the latter. We develop these models more fully to account for general relativistic effects and to focus on advection-dominated accretion flows (ADAFs) for which the jet power is expected to be a significant fraction of the accreted rest mass energy. We apply the models to elliptical galaxies, in order to see if these models can explain the observed correlation between the Bondi accretion rates and the total jet powers. For typical values of the disc viscosity parameter α ~ 0.04–0.3 and mass accretion rates consistent with ADAF model expectations, we find that the observed correlation requires j > ~ 0.9; that is, it implies that the black holes are rapidly spinning. Our results suggest that the central black holes in the cores of clusters of galaxies must be rapidly rotating in order to drive jets powerful enough to heat the intracluster medium and quench cooling flows.en
dc.format.mimetypeapplication/pdf
dc.language.isoengpt_BR
dc.relation.ispartofMonthly notices of the royal astronomical society. Vol. 377, no. 4 (June 2007), p. 1652-1662pt_BR
dc.rightsOpen Accessen
dc.subjectAccretion, accretion discsen
dc.subjectBuracos negrospt_BR
dc.subjectBlack hole physicsen
dc.subjectGalaxias elipticaspt_BR
dc.subjectMHDen
dc.subjectGalaxies: activeen
dc.subjectGalaxies: jetsen
dc.subjectX-rays: galaxiesen
dc.titleModels for jet power in elliptical galaxies : a case for rapidly spinning black holespt_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb000604263pt_BR
dc.type.originEstrangeiropt_BR


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