Molecular gas in the z=2.565 submillimeter galaxy SMM J14011+0252

We report the detection of CO (3-->2) emission from the submillimeter-selec ted luminous galaxy SMM J14011 + 0252. The optical counterpart of the submi llimeter source has been identified as a merger system with spectral charac teristics consistent with a starburst at z = 2.565. The CO emission confirm s the optical identification of the submillimeter source and implies a mole cular gas mass of 5 x 10(10) h(75)(-3) M-., after correcting for a lensing amplification factor of 2.75, The large molecular gas mass and the radio em ission are consistent with the starburst interpretation of the source. Thes e results are similar to those found for SMM J02399-0136, which was the fir st submillimeter-selected CO source found at high redshift. The CO detectio ns of these two high-redshift submillimeter galaxies suggest the presence o f massive reservoirs of molecular gas, which is consistent with the inferre d high rates of star formation (10(3) M-. yr(-1)). These two systems appear to be associated with merger events which may evolve into present-day lumi nous elliptical galaxies.