2007ApJ...666L...9C

We have detected emission by the CO(5-4) and (6-5) rotational transitions at z=5.7722±0.0006 from the host galaxy of the SDSS quasar J0927+2001 using the Plateau de Bure Interferometer. The peak line flux density for the CO(5-4) line is 0.72±0.09 mJy, with a line FWHM = 610±110 km/s. The implied molecular gas mass is (1.6±0.3)x10¹⁰ M_☉. We also detect the 90 GHz continuum at 0.12±0.03 mJy, consistent with a 47 K dust spectrum extrapolated from higher frequencies. J0927+2001 is the second example of a huge molecular gas reservoir within the host galaxy of a quasar within 1 Gyr of the big bang. Observations of J0927+2001 are consistent with a massive starburst coeval with a bright quasar phase in the galaxy, suggesting the rapid formation of both a supermassive black hole through accretion, and the stellar host spheroid, at a time close to the end of cosmic reionization.