1999ApJ...521L..25C

We have detected redshifted CO (2-1) emission at 43 GHz and radio continuum emission at 1.47 and 4.86 GHz from the z=4.4 QSO BRI 1335-0417 using the Very Large Array. The CO data imply optically thick emission from warm (>30 K) molecular gas with a total mass, M(H₂), of (1.5±0.3)x10¹¹ M_☉, using the standard Galactic gas mass-to-CO luminosity conversion factor. We set an upper limit to the CO source size of 1".1 and a lower limit of 0".23(T_ex/50 K)^–1/2, where T_ex is the gas excitation temperature. We derive an upper limit to the dynamical mass of 2x10¹⁰sin\ul -2i M_☉, where i is the disk inclination angle. Reconciling the gas mass with the dynamical mass requires either a nearly face-on disk (i<25°) or a gas mass-to-CO luminosity conversion factor significantly lower than the Galactic value. The spectral energy distribution from the radio to the rest-frame infrared of BRI 1335-0417 is consistent with that expected from a nuclear starburst galaxy, with an implied massive star formation rate of 2300±600 M_☉.yr^–1.