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Paper: The UGC FR 1 radio galaxy sample: which giant ellipticals can host radio-jets?
Volume: 290, Active Galactic Nuclei: from Central Engine to Host Galaxy
Page: 259
Authors: Verdoes Kleijn, G.; Baum, S.; van der Marel, R.; O'Dea, C.; Noel-Storr, J.; van Gorkom, J.; de Zeeuw, T.
Abstract: Nuclear dust and neutral and ionized gas is present in the cores of many nearby active and quiescent early-type galaxies. The properties which are decisive in triggering nuclear activity and the origin and ionization mechanism of the interstellar material are not well known. To address these issues an overview is presented of results from radio and HST optical imaging and spectroscopic observations for a sample of 21 nearby radio galaxies, the `UGC FR I sample'. Constraints on the origin and Doppler boosting of AGN emission from correlations between broad- and narrowband AGN emission are described as well as the relative orientation of central dust features, galaxies and radio-jets. Gas kinematics for the sample and dynamical modeling of gas disks to determine central black hole (BH) masses are presented and the validity and accuracy of the gas dynamical method to derive BH masses in comparison to other methods to obtain BH masses is discussed. These results are then compared to those for nearby quiescent and radio-quiet active nuclei in other early-type galaxies. This allows us to determine relationships between the level of nuclear activity on the one hand and host and gas disk properties and BH mass on the other hand. The constraints placed by these on the triggering mechanism for activity and origin and ionization mechanism of interstellar matter in the nuclei of nearby early-type galaxies are discussed.
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