Evidence for extended gaseous reservoirs around AGN at cosmic noon from ALMA CO(3-2) observations

Understand

Gaseous outflows are key phenomena in the evolution of galaxies, as they affect star formation (either positively or negatively), eject gas from the core or disk, and directly cause mixing of pristine and processed material.

• Active outflows may be detected through searches for broad spectral line emission or high-velocity gas, but it is also possible to determine the presence of past outflows by searching for extended reservoirs of chemically enriched molecular gas in the circumgalactic medium (CGM) around galaxies.
• In this work, we examine the CO(3-2) emission of a set of seven z~2.0-2.5 AGN host galaxies, as observed with ALMA.
• Through a three-dimensional stacking analysis we find evidence for extended CO emission of radius r~13kpc.