1999AJ....117.1139W

We searched for 22 GHz water maser emission from two gravitationally lensed quasars, H1413+117 (the Cloverleaf) at z=2.56 and MG 0414+0534 at z=2.64, using the Australia Telescope Compact Array. Detections of CO emission at millimeter wavelengths from these systems provide the redshifts of the molecular components with high precision and suggest substantial reservoirs of molecular gas. The observations were made with ∼750 km.s^–1 of velocity coverage, enough to span the entire range of CO emission. No narrow water maser features were found in the observed bands in either source, though the sensitivities achieved were sufficient for detection if either (1) the water maser luminosity were substantially larger than found in nearby low-power active galactic nuclei (AGNs), which maser theory suggests is plausible, or (2) the water maser luminosity were typical of nearby detected AGNs but magnified by an extremely large factor, as might be the case near a lens caustic. The detection limits for a 1.5 km.s^–1 channel correspond to isotropic maser luminosities of a few 1000(m/10)^–1 L_☉, where m is the lensing magnification factor, values that are comparable to the most luminous AGN water masers in the local universe for m~10.