Sensitive Radio Observations of High-Redshift Dusty QSOs

We present sensitive radio continuum imaging at 1.4 GHz and 4.9 GHz of seven high redshift QSOs selected for having a 240 GHz continuum detection, which is thought to be thermal dust emission. We detect radio continuum emission from four of the sources: BRI 0952−0115, BR 1202−0725, LBQS 1230+1627B, and BRI 1335−0417. The radio source in BR 1202−0725 is resolved into two components, coincident with the double mm and CO sources. We compare the results at 1.4 GHz and 240 GHz to empirical and semi-analytic spectral models based on star forming galaxies at low redshift. The radio-to-submm spectral energy distribution for BR 1202−0725, LBQS 1230+1627B, and BRI 1335−0417 are consistent with that expected for a massive starburst galaxy, with implied massive star formation rates of order 10 M⊙ year −1 (without correcting for possible amplification by gravitational lensing). The radio-to-submm spectral energy distribution for BRI 0952−0115 suggests a low-luminosity radio jet source driven by the AGN.