A detection of [C II] line emission in the z=4.7 QSO BR 1202-0725

We present similar to 3(n) resolution imaging of the z = 4.7 QSO BR 1202-0725 at 900 mm from the Submillimeter Array. The two submillimeter continuum components are clearly resolved from each other, and the positions are consistent with previous lower frequency images. In addition, we detect [C II] line emission from the northern component at L-[C II] = 4.5 x 10(9) L-circle dot. The ratio of [C II] to far-infrared luminosity is 0.04% for the northern component, and an upper limit of < 0.03% is obtained for the southern component. These ratios are similar to the low values found in local ultraluminous galaxies, indicating that the excitation conditions are different from those found in local field galaxies. X-ray emission is detected by Chandra from the southern component at L0.5-2 keV = 3 x 10(45) ergs s(-1) and, at 99.6% confidence, from the northern component at L0.5-2 keV similar to 3 x 10(44) ergs s(-1), supporting the idea that BR 1202-0725 is a pair of interacting galaxies at and that each harbors z = 4.7 an active nucleus.