A Detection of [CII] line emission in the z=4.7 QSO BR1202-0725

Abstract

We present ~3'' resolution imaging of the z=4.7 QSO BR1202-0725 at 900 micron 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 [CII] line emission from the northern component. The ratio of [CII] 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 L$_{0.5-2keV}=3\times10^{45}$~erg~s$^{-1}$, and detected at 99.6% confidence from the northern component at L$_{0.5-2keV}\sim3\times10^{44}$erg~s$^{-1}$, supporting the idea that BR1202-0725 is a pair of interacting galaxies at z=4.7 that each harbor an active nucleus.