We use a sample of powerful z \approx 0.1 type 2 quasars ( ‘ obscured ’ ; \log [ L _ { \text { AGN } } /erg s ^ { -1 } ] \gtrsim 45 ) , which host kiloparsec-scale ionized outflows and jets , to identify possible signatures of AGN feedback on the total molecular gas reservoirs of their host galaxies .
Specifically , we present Atacama Pathfinder EXperiment ( APEX ) observations of the CO ( 2–1 ) transition for nine sources and the CO ( 6–5 ) for a subset of three .
We find that the majority of our sample reside in starburst galaxies ( average specific star formation rates of 1.7 Gyr ^ { -1 } ) , with the seven CO-detected quasars also having large molecular gas reservoirs ( average M _ { \textrm { gas } } =1.3 \times 10 ^ { 10 } M _ { \odot } ) , even though we had no pre-selection on the star formation or molecular gas properties .
Despite the presence of quasars and outflows , we find that the molecular gas fractions ( M _ { \textrm { gas } } /M _ { \star } =0.1–1.2 ) and depletion times ( M _ { \textrm { gas } } /SFR=0.16–0.95 Gyr ) are consistent with those expected for the overall galaxy population with matched stellar masses and specific star formation rates .
Furthermore , for at least two of the three targets with the required measurements , the CO ( 6–5 ) /CO ( 2–1 ) emission-line ratios are consistent with star formation dominating the CO excitation over this range of transitions .
The targets in our study represent a gas-rich phase of galaxy evolution with simultaneously high levels of star formation and nuclear activity ; furthermore , the jets and outflows do not have an immediate appreciable impact on the global molecular gas reservoirs .