Spectroscopic Confirmation of an Extreme Starburst at Redshift 4.547
Résumé
We report the spectroscopic confirmation of a submillimeter galaxy (SMG) at z = 4.547 with an estimated LIR = (0.5-2.0) × 1013 L⊙. The spectra, mid-IR, and X-ray properties indicate the bolometric luminosity is dominated by star formation at a rate of >1000 M⊙ yr-1. Multiple, spatially separated components are visible in the Lyα line with an observed velocity difference of up to 380 km s-1 and the object morphology indicates a merger. The best-fit spectral energy distribution and spectral line indicators suggest the object is 2-8 Myr old and contains >1010 M⊙ of stellar mass. This object is a likely progenitor for the massive early-type systems seen at z ~ 2. Based on observations taken at the Keck Observatory, the James Clerk Maxwell Telescope, the Institut de Radioastronomie Millimetrique 30 m telescope, the Galaxy Evolution Explorer, the Chandra X-Ray Observatory, the Hubble Space Telescope, the Very Large Array, the Subaru Telescope, the United Kingdom Infrared Telescope, and the Canada-France-Hawaii Telescope.