Carbon monoxide in a remote galaxy

Spectrum of a very distant quasar on which the footprints from a galaxy located almost 11 billion light-years away are seen. Various bands of carbon monoxide (CO), as well as bands of normal and deuterated molecular hydrogen (H2, HD) were identified by the astronomers. The different intensities of the CO bands allow the astronomers to infer the temperature of the Cosmic Background Radiation at this very remote epoch. The spectrum was obtained with UVES on ESO's VLT. It is the result of more than 8 hours of observations.