AGN on the Beach

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A Multi-frequency Analysis of the Timescales Associated with AGN Activity in a Jetted Green Bean Galaxy

Kelly Sanderson

 We, 11:35 ! Livein  Palazzo Santa Chiarafor  15min

Jetted AGN that host extended ionized nebulae provide us with a unique view of the timescales associated with AGN activity. Here we present a multi-frequency analysis of one such source caught in a moment where the properties of the central engine have changed. Specifically, we use radio observations to constrain the time since the last reacceleration of charged particles in the radio galaxy hotspots of the system, and optical long-slit spectroscopy to estimate the redshift and kinematic properties of the host galaxy, and the light travel time needed to ionize the extended gas around the AGN. The data suggest that the AGN was previously in a low accretion state associated with the production of radio jets, but has since transitioned to a state of higher accretion associated with ionizing the extended gas around it. We discuss the possibilities that the AGN underwent this transition either via AGN flickering, or via an accretion state transition as seen in Galactic X-ray binaries. We also discuss possible explanations for the unusual apparent hybrid radio morphology of the source, including the presence of a detached cloud coincident with one of the radio hot spots in the circum-galactic medium of the system.

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