CO Emission in Infrared-Selected Active Galactic Nuclei

Understand

In order to better understand how active galactic nuclei (AGN) effect the interstellar media of their host galaxies, we perform a meta-analysis of the CO emission for a sample of $z=0.01-4$ galaxies from the literature with existing CO detections and well-constrained AGN contributions to the infrared (67 galaxies).

• Using either Spitzer/IRS mid-IR spectroscopy or Spitzer+Herschel colors we determine the fraction of the infrared luminosity in each galaxy that can be attributed to heating by the AGN or stars.
• We calculate new average CO spectral line ratios (primarily from Carilli \& Walter 2013) to uniformly scale the higher-$J$ CO detections to the ground state and accurately determine our sample's molecular gas masses.
• We do not find significant differences in the gas depletion timescales/star formation efficiencies (SFEs) as a function of the mid-infrared AGN strength ($f_{\rm AGN}({\rm MIR})$ or $L_{\rm IR} ({\rm AGN})$), which indicates that the presence of an IR-bright AGN is not a sufficient sign-post of galaxy quenching.