We present a comprehensive study of the molecular gas properties of 17 Type 2
quasars at z10^{42.1}\rm ergs^{-1}),selectedbytheirhigh[OIII]luminositiesanddisplayingalargediversityofradiojetproperties,butdominatedbyLIRG−likegalaxies.Withthesedata,weareabletoinvestigatetheimpactofAGNandAGNfeedbackmechanismsontheglobalmolecularinterstellarmedium.UsingAPEXandALMAACAobservations,wemeasurethetotalmoleculargascontentusingtheCO(1−0)emissionandhomogeneouslysampletheCOspectrallineenergydistributions(SLEDs),observingCOtransitions(J_{up}=1,2,3,6,7).Weobservehighr_{21}ratios(r_{21}=L′_{CO(2-1)}/L′_{CO(1-0)})withamedianr_{21}=1.06,similartolocal(U)LIRGs(withr_{21}\sim1)andhigherthannormalstar−forminggalaxies(withr_{21}\sim0.65).Despitethehighr_{21} values, for the 7
targets with the required data we find low excitation in CO(6-5) & CO(7-6)
(r_{61}andr_{62}$ < 0.6 in all but one target), unlike high redshift
quasars in the literature, which are far more luminous and show higher line
ratios. The ionised gas traced by [OIII] exhibit systematically higher
velocities than the molecular gas traced by CO. We conclude 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.Comment: 32 pages (20 in the main body of the paper and 12 in the appendix),
28 figures (10 in main body of paper and 18 in appendix) Accepted for
publication in MNRAS. Data available at
https://doi.org/10.25405/data.ncl.2431250