We present a study of the stellar host galaxy , CO ( 1–0 ) molecular gas distribution and AGN emission on 50 to 500 pc-scales of the gravitationally lensed dust-obscured AGN MG J0751+2716 and JVAS B1938+666 at redshifts 3.200 and 2.059 , respectively .
By correcting for the lensing distortion using a grid-based lens modelling technique , we spatially locate the different emitting regions in the source plane for the first time .
Both AGN host galaxies have 300 to 500 pc-scale size and surface brightness consistent with a bulge/pseudo-bulge , and 2 kpc-scale AGN radio jets that are embedded in extended molecular gas reservoirs that are 5 to 20 kpc in size .
The CO ( 1–0 ) velocity fields show structures possibly associated with discs ( elongated velocity gradients ) and interacting objects ( off-axis velocity components ) .
There is evidence for a decrement in the CO ( 1–0 ) surface brightness at the location of the host galaxy , which may indicate radiative feedback from the AGN , or offset star formation.We find CO–H _ { 2 } conversion factors of around \alpha _ { CO } = 1.5 \pm 0.5 ( K km s ^ { -1 } pc ^ { 2 } ) ^ { -1 } , molecular gas masses of > 3 \times 10 ^ { 10 } M _ { \odot } , dynamical masses of \sim 10 ^ { 11 } M _ { \odot } and gas fractions of around 60 per cent .
The intrinsic CO line luminosities are comparable to those of unobscured AGN and dusty star-forming galaxies at similar redshifts , but the infrared luminosities are lower , suggesting that the targets are less efficient at forming stars .
Therefore , they may belong to the AGN feedback phase predicted by galaxy formation models , because they are not efficiently forming stars considering their large amount of molecular gas .