Detection of $1.6\times 10^{10}$ M${}_{\odot }$ of molecular gas in the host galaxy of the $z=5.77$ SDSS quasar J0927+2001

Abstract

We have detected emission by the CO 5-4 and 6-5 rotational transitions at $z=5.7722\pm 0.0006$ 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 $0.72\pm 0.09$ mJy, with a line FWHM = $610\pm 110$ km s${}^{-1}$. The implied molecular gas mass is $(1.6\pm 0.3)\times 10^{10}$ M${}_{\odot }$. We also detect the 90 GHz continuum at $0.12\pm 0.03$ mJy, consistent with a 47K 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 super-massive black hole through accretion, and the stellar host spheroid, at a time close to the end of cosmic reionization.

12 pages, 2 figures, to appear in ApJ Letters