A Look at AGN Feedback in Local Palomar-Green Quasar Host Galaxies – Juan Molina

Since the discovery of the coevolution between supermassive black holes (BHs) and their host galaxies, many efforts have been made to understand the role of active galactic nucleus (AGN) feedback as the mediating mechanism. AGN feedback in the form of multi-phase gas outflows may be powerful enough to heat or expel the host galaxy’s interstellar medium (ISM), thereby halting ongoing star formation and keeping the host galaxy quiescent. However, despite compelling evidence of multi-phase gas outflows in AGN host galaxies, observational campaigns have provided no definitive answer. Empirical correlations between AGN strength and outflow properties suggest that AGN-driven outflows are stronger in more luminous AGNs (i.e., quasars). Strikingly, more luminous AGNs are often found in host galaxies with higher rates of star formation and normal cold gas reservoirs. By measuring the global properties of AGN host galaxies, studies find no significant difference compared to those of inactive galaxies, suggesting low AGN feedback effectiveness. However, this is consistent with hydrodynamical simulations that rely on negative AGN feedback to drive galaxy evolution in massive systems. Lacking clear evidence for or against AGN feedback in influencing galaxy evolution, the next step is to study the internal properties of AGN host galaxies. In this talk, I will provide an overview of my recent work based on ALMA and MUSE observations that spatially resolve the ISM of a subset of local Palomar-Green quasar host galaxies.