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dc.contributor.authorEdmonds, Bartlett D.en_US
dc.date.accessioned2013-09-11T08:00:21Z
dc.date.available2013-09-11T08:00:21Z
dc.date.issued2013-09-10en_US
dc.identifier.othervt_gsexam:1594en_US
dc.identifier.urihttp://hdl.handle.net/10919/23767
dc.description.abstractActive galactic nuclei (AGN) ubiquitously show outflows. It is now widely recognized that these outflows are key components in the evolution of super-massive black holes and their host galaxies. As important as these outflows are, we still lack sufficient understanding of their structure and energetics. The majority of the work presented in this thesis involved photoionization modeling of AGN outflows along with analysis of density diagnostics in order to determine the distances and energetics of observed outflows. The main findings of these analyses are that 1) outflows are often at distances of hundreds to thousands of parsecs from the central supermassive black hole and 2) quasars outflows can be sufficiently powerful to provide feedback in galactic evolution scenarios. We also find in some cases that the recombination timescales of metal ions are long compared with the flux variability timescales. The large distances we find provide a challenge to current outflow models. For example, these outflows cannot be connected with an accretion disk surrounding the supermassive black hole as assumed in some models. Furthermore, the outflows may be out of equilibrium as we find in Mrk 509. In this case, a thorough understanding of time-dependent photoionization effects is necessary. In this thesis, I include early steps toward understanding time-dependent photoionization as well as ionization studies of accretion disk winds. The main results of these theoretical studies is that 1) the appearance of multiple ionization components in an outflow can be an artifact of the incorrect assumption that the outflow is in ionization equilibrium and 2) the shielding gas required in accretion-disk-wind models should have a clear signature in UV spectra, but none has been observed to date.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectActive galactic nucleien_US
dc.subjectAGN outflowsen_US
dc.subjectQuasaren_US
dc.subjectQuasar outflowen_US
dc.subjectSeyfert galaxiesen_US
dc.titleOn the Distances and Energetics of AGN Outflowsen_US
dc.typeDissertationen_US
dc.contributor.departmentPhysicsen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplinePhysicsen_US
dc.contributor.committeechairArav, Nahumen_US
dc.contributor.committeememberSharpe, Eric R.en_US
dc.contributor.committeememberPitt, Mark L.en_US
dc.contributor.committeememberSimonetti, John H.en_US


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