Speaker
Description
We investigate the different modes of energy output from active galactic nuclei (AGN) and their connection to black-hole growth in radio-selected galaxies. To achieve this, we use the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Early Science catalogue from the COSMOS field observed at 1.28 GHz, which was derived from an image with a median rms of 2 $\mu$Jy beam$^{-1}$. This catalogue contains 5223 radio sources with optical and near-infrared detections traced up to redshift $z$ $\approx$ 6. Using the CIGALE spectral energy distribution (SED) fitting code, we determine the stellar masses ($M_{\star}$), star formation rates (SFRs), black-hole mass (M$_{\rm BH}$), and AGN luminosity (L$_{\rm AGN}$) of the sources. Using the evolving star-forming main sequence, we classify the radio sources as star-forming (30 $\pm$ 1$\%$), intermediate (31 $\pm$ 1$\%$), or passive (39 $\pm$ 2$\%$) galaxies, and further divide them into low- and high-accretion modes (LAM and HAM) using their Eddington-scaled accretion rates. We find that LAM AGN reside preferentially in more massive, lower-SFR hosts than HAM AGN, suggesting differences in the availability of cold gas that fuels both star formation and AGN activity. We further investigate the relationship between AGN luminosity and black-hole mass across the six host-galaxy and accretion-mode populations. Using 1.4 GHz radio luminosity as a tracer of mechanical power from AGN jets, we will compare the radiative and mechanical outputs across these populations to explore how AGN energy output varies with accretion state and host-galaxy properties.