Searching for the 380 GHz H2O emission from the high-z lensed quasi-stellar object MG J0414+0534

Abstract

Abstract We report the results of our search for the 380 GHz H2O line emissions from the quadruply lensed quasi-stellar object (QSO) MG J0104+0534 at z = 2.639 with the Atacama Large Millimeter/submillimeter Array. Our observation shows a tentative detection of the 380 GHz line from the lensed QSO, and the line spectrum shows a broad spectral distribution that has a velocity width of ∼290 km s−1 and a peak flux of ∼0.8 mJy. The integrated intensity map of the H2O line shows lensed emissions at the A1 and A2 component of the QSO, with the A2 component slightly resolved. The integrated line flux ratio between the A1 and A2 components shows an unexpected difference from the continuum flux ratio. Based on our gravitational lens modeling, assuming our tentative detection is real, this flux ratio anomaly would suggest that the 380 GHz line emissions come from two or three spatially displaced locations in the QSO, with the dominant one located at the position of the continuum emission from the QSO, and the other one(s) displaced from the continuum by ∼1.5 kpc on the source plane.