Interferometric observations of powerful CO emission from three submillimeter galaxies at z=2.39, 2.51, and 3.35

We report IRAM millimeter interferometry of three zsimilar to2.4-3.4 Submillimeter Common-User Bolometric Array deep field galaxies. Our CO line observations confirm the rest-frame UV/optical redshifts, thus more than doubling the number of confirmed published redshifts of the faint submillimeter population and proving their high-z nature. In all three sources our measurements of the intrinsic gas and dynamical mass are large (10(10)-10(11) M-circle dot). In at least two cases the data show that the submillimeter sources are part of an interacting system. Together with recent information gathered in the X-ray, optical, and radio bands, our observations support the interpretation that the submillimeter population, at least the radio-detected ones, consists of gas-rich (gas-to-dynamical mass ratio similar to0.5) and massive interacting starburst/active galactic nucleus systems.