The demographics of radio-AGN activity from LoTSS and SDSS
The combination of the vast, high-sensitivity radio catalogues being produced by the LOFAR Two-Metre Sky Survey (LoTSS), with the large spectroscopic samples made available through SDSS, provides a remarkable resource to understand the triggering, evolution and feedback effects of radio-AGN in the nearby Universe. Using these data, we confirm the existence of the tight fundamental plane of black hole activity (jet power vs accretion power vs black hole mass) using tens of thousands of local AGN, and characterise the additional galaxy parameters that produce the scatter in the relation. We also measure the prevalence of different classes of radio-AGN activity as multi-variate functions of stellar mass, black hole mass, environment and galaxy morphology. Once the strong stellar mass dependence is accounted for, we find no dependence of radio-AGN activity on either black hole mass or morphology, but do find enhanced radio luminosities in higher density environments. These results imply that the triggering of radio-AGN activity is controlled by processes on galactic scales or larger. We discuss the implications of this result for radio-AGN fuelling and the radio-AGN feedback cycle.