Izumi ,T.Matsuoka, Y.Onoue, M.Strauss, M. A.Umehata, H.Silverman, J. D.Nagao, T.Imanishi, M.Kohno, K.Toba, Y.Iwasawa, KazushiNakanish,i K.Sawamura, M.Fujimoto, S.Kikuta, S.Kawaguchi, T.Aoki, K.Goto, T.2025-01-302025-01-3020240004-637Xhttps://hdl.handle.net/2445/218249We present Atacama Large Millimeter/submillimeter Array [C ii] 158 μm line and underlying far-IR continuum emission observations (0farcs57 × 0farcs46 resolution) toward a quasar–quasar pair system recently discovered at z = 6.05. The quasar nuclei (C1 and C2) are faint (M1450 ≳ −23 mag), but we detect very bright [C ii] emission bridging the 12 kpc between the two objects and extending beyond them (total luminosity L[C ii] ≃ 6 × 109L⊙). The [C ii]-based total star formation rate of the system is ∼550 M⊙ yr−1 (the IR-based dust-obscured star formation is ∼100 M⊙ yr−1), with a [C ii]-based total gas mass of ∼1011M⊙. The dynamical masses of the two galaxies are large (∼9 × 1010M⊙ for C1 and ∼5 × 1010M⊙ for C2). There is a smooth velocity gradient in [C ii], indicating that these quasars are a tidally interacting system. We identified a dynamically distinct, fast-[C ii] component around C1: detailed inspection of the line spectrum there reveals the presence of a broad-wing component, which we interpret as the indication of fast outflows with a velocity of ∼600 km s−1. The expected mass-loading factor of the outflows, after accounting for multiphase gas, is ≳2 − 3, which is intermediate between AGN-driven and starburst-driven outflows. Hydrodynamic simulations in the literature predict that this pair will evolve to a luminous (M1450 ≲ −26 mag), starbursting (≳1000 M⊙ yr−1) quasar after coalescence, one of the most extreme populations in the early Universe.1 p.application/pdfeng(c) American Astronomical Society, 2024GalàxiesQuàsarsGalaxiesQuasarsinfo:eu-repo/semantics/article7537922025-01-30info:eu-repo/semantics/openAccess