Dust, gas, and the evolutionary status of the radio galaxy 8C 1435+635

摘要

We present the results of new rest-frame far-IR observations of the z = 4.25 radio galaxy 8C 1435+635, which not only confirm that it contains an enormous quantity of dust (as inferred from its millimeter-wave detection by Ivison in 1995), but also allow the first meaningful constraints to be placed on the mass of this dust and associated gas. The new measurements consist of (1) clear detections of submillimeter continuum emission at λ_obs = 450 and 850 μm obtained with the new submillimeter bolometer array, SCUBA, on the James Clerk Maxwell Telescope, (2) continuum upper limits at λ_obs = 350, 750, and 175 μm obtained with SCUBA and the PHT far-IR camera aboard the Infrared Space Observatory, and (3) a sensitive upper limit on the CO(4-3) line flux obtained with the IRAM 30 m Millimeter Radio Telescope.