A Luminous Molecular Gas Pair beyond Redshift 7

We report the first detection of molecular gas beyond redshift 7. The molecular gas is associated with the host galaxy of the quasar candidate PSO J145.5964+19.3565 and its companion PSO J145.5964+19.3565N separated by 20.7 kpc. The molecular gas of both companions is detected in two rotational transition lines of carbon monoxide, CO(6–5) and CO(7–6), with total luminosities of ${L}_{\mathrm{CO}(6-5)}\approx 26\times {10}^{8}$ and ${L}_{\mathrm{CO}(7-6)}\approx 17\times {10}^{8}$ L⊙. The two companions contain (36–54) × 1010 M⊙ of molecular gas assuming that their CO spectral line energy distributions are typical for star-forming galaxies. We also detected the Lyα line of PSO J145.5964+19.3565 at z ≈ 7.08. The Lyα line emission is extended and might represent the blended emission of two different sources at a separation of <5 kpc. The detected CO and Lyα emission likely originate from a system of interacting star-forming galaxies that might host a quasar(s). We also report the detection of a new emission line from the system that is a possible 793.62-GHz water maser line.