Detection of CO (2-1) and Radio Continuum Emission from the z = 4.4 QSO BRI 1335–0417
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) × 1011 Msun, using the standard Galactic gas mass-to-CO luminosity conversion factor. We set an upper limit to the CO source size of 1farcs1 and a lower limit of 0farcs23(Tex/50 K)-1/2, where Tex is the gas excitation temperature. We derive an upper limit to the dynamical mass of 2 × 1010sin−2 i Msun, 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 Msun yr-1.
C L. Carilli, Karl M. Menten, and Min S. Yun. "Detection of CO (2-1) and Radio Continuum Emission from the z = 4.4 QSO BRI 1335–0417" Astrophysical Journal Letters 521.1 (1999): L25-L28.
Available at: http://works.bepress.com/min_yun/72