PhD Proposal: Mary Keenan
TITLE: Unification Schemes in Radio Loud AGN
ABSTRACT:Radio-loud Active Galactic Nuclei are actively accreting super-massive black holes with large-scale jets of relativistic plasma propagating away from the central engine. Slowed plasma from these jets accumulates into giant radio lobes, resulting in an isotropic synchrotron emission which dominates at low radio frequencies. This isotropic luminosity has been shown to correlate with the kinetic power of the jet, Lkin, (Cavagnolo et al., 2010; Ineson et al., 2017) and thus serves as a viable method of estimating the total power carried by it. Here, two projects are proposed, both applications of low frequency measurements as a proxy for jet power, as we believe Lkin is fundamental in unveiling the nature of the jet.
For the first project, a large catalog of jet proper motions, as measured by VLBI, has been compiled in order to investigate the relation between the apparent speeds, βapp, and Lkin, and to examine the nature of the Lorentz factor, Γ, of the underlying flow. We have found preliminary evidence that Lkin sets an upper bound on the Γ of the plasma components that are ejected from the core, and are currently investigating the nature of this bound.
The second project will revisit the blazar envelope by Meyer et al. (2011), which introduces a dichotomy of jets, broken down into ‘strong’ and ‘weak’ source classes. This project will look further into this dichotomy, investigating the roles of Lkin, black hole mass, and the accretion efficiency. It will also look further into the characteristics of the Inverse Compton emission at high energies. Finally, the nature of outliers which appear to ‘break the blazar sequence’ will be investigated.