Speaker
Description
Brightest cluster galaxies (BCGs) host powerful active galactic nuclei (AGN) that regulate the heating–cooling balance of the intracluster medium. We study AGN activity in 171 BCGs in Sunyaev–Zel’dovich selected clusters from the AdvACT survey over 0.3 < z < 0.8 using SALT spectroscopy, WISE mid-infrared photometry, ASKAP RACS radio data, and X-CIGALE SED modelling. We find that 26% of BCGs host radio-loud AGN, predominantly low-excitation radio galaxies (LERGs). The derived Eddington ratios indicate mainly radiatively inefficient accretion consistent with maintenance-mode feedback. Accretion efficiency increases modestly with redshift but shows little dependence on cluster halo mass, suggesting that AGN activity in BCGs is regulated primarily by gas supply in cluster cores rather than the global gravitational potential.
| Stream | Science or Engineering |
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