Speaker
Description
Feedback from radio AGN has been observed in the form of jet driven gas outflows, which can affect the host galaxy’s evolution. Radio AGN are also known to have a life-cycle of activity. However it is still not completely clear how feedback evolves with the AGN life-cycle. In the first part of my talk, I will discuss our results from a study to investigate this with a sample of uniformly selected 129 radio AGN up to z=0.2 and L(1.4 GHz)=1e26 W/Hz. We used radio spectral shape from 144-3000 MHz (LoTSS, FIRST, VLASS) as a proxy for the evolutionary stage of the AGN, and [OIII] spectra to trace the warm ionised gas kinematics. We found that outflows in young sources (peaked radio spectrum) were more extreme than evolved sources (non-peaked), and are typically short lived. This was true even if we included the [OIII] non-detections and used a stacking analysis, showing this is true on average for the radio AGN population. For candidate restarted AGN, we found tentative evidence for more disturbed gas kinematics, suggesting a link with episodic jet activity. We also found that radio luminosity, optical luminosity, ionisation state and accretion rate did not play a definitive role in driving feedback in our sample.
In the second part, I will discuss new results from an expansion of this study to ~5500 sources, up to z=0.8 and L(1.4 GHz)=1e28 W/Hz. Our findings support the picture from simulations where impact of feedback changes as the radio jets grow.
