ALMA detections of CO emission in the most luminous, heavily dust-obscured quasars at z>3.

We report the results of a pilot study of CO$(4-3)$ emission line of three {\it WISE}-selected hyper-luminous, dust-obscured quasars (QSOs) with sensitive ALMA band-3 observations. These obscured QSOs with $L_{\rm bol}>10^{14}L_\odot$, among the most luminous object in the Universe, have been suggested to be located at or close to both peaks of supermassive black hole (SMBH) accretion and starburst activity. All three QSO hosts are clearly detected both in continuum and in CO$(4-3)$ emission line. Based on CO(4-3) emission line detection, we derive the molecular gas masses ($\sim 10^{10-11}$ M$_\odot$), suggesting that these QSOs are gas-rich systems. We find that three obscured QSOs in our sample follow the similar $L'_{\rm CO}- L_{\rm FIR}$ relation as unobscured QSOs at high redshift. We also find the complex velocity structures of CO(4-3) emission line, which provide the possible evidence for gas-rich merger in W0149+2350 and massive molecular outflow in W0220+0137 and W0410$-$0913. Massive molecular outflow can blow away the obscured interstellar medium (ISM) and make obscured QSOs evolve towards the UV/optical bright, unobscured phase. Our result is consistent with the popular AGN feedback scenario involving the co-evolution between the SMBH and host galaxy.