Characterising CO excitation in quasar host galaxies 

During my studentship placement at ESO I worked as part of the Quasar Feedback Survey Team and performed a comprehensive study of the molecular gas properties of 17 Type 2 quasars at 𝑧 < 0.2. I was able to investigate the impact of AGN and AGN feedback mechanisms on the global molecular interstellar medium. Using APEX and ALMA ACA observations, we measured the total molecular gas content using the CO(1-0) emission and homogeneously sample the CO spectral line energy distributions (SLEDs), observing CO transitions (J𝑢 𝑝 = 1, 2, 3, 6, 7). We concluded that any effects of quasar feedback (e.g. via outflows and radio jets) do not have a significant instantaneous impact on the global molecular gas content and excitation and we suggest that it only occurs on more localised scales (Molyneux et al. 2023).