A Dust-Obscured Massive Maximum-Starburst Galaxy at a Redshift of 6.34
Abstract
Massive present-day early-type (elliptical and lenticular) galaxies probably gained the bulk of their stellar mass and heavy elements through intense, dust-enshrouded starbursts - that is, increased rates of star formation - in the most massive dark matter halos at early epochs. However, it remains unknown how soon after the Big Bang such massive starburst progenitors exist. The measured redshift distribution of dusty, massive starbursts has long been suspected to be biased low in redshift owing to selection effects, as confirmed by recent findings of systems out to redshift z~5. Here we report the identification of a massive starburst galaxy at redshift 6.34 through a submillimeter color-selection technique. We unambiguously determined the redshift from a suite of molecular and atomic fine structure cooling lines. These measurements reveal a hundred billion solar masses of highly excited, chemically evolved interstellar medium in this galaxy, which constitutes at least 40% of the baryonic mass. A "maximum starburst" converts the gas into stars at a rate more than 2,000 times that of the Milky Way, a rate among the highest observed at any epoch. Despite the overall downturn of cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.
Keywords
Cite
@article{arxiv.1304.4256,
title = {A Dust-Obscured Massive Maximum-Starburst Galaxy at a Redshift of 6.34},
author = {Dominik A. Riechers and C. M. Bradford and D. L. Clements and C. D. Dowell and I. Perez-Fournon and R. J. Ivison and C. Bridge and A. Conley and Hai Fu and J. D. Vieira and J. Wardlow and J. Calanog and A. Cooray and P. Hurley and R. Neri and J. Kamenetzky and J. E. Aguirre and B. Altieri and V. Arumugam and D. J. Benford and M. Bethermin and J. Bock and D. Burgarella and A. Cabrera-Lavers and S. C. Chapman and P. Cox and J. S. Dunlop and L. Earle and D. Farrah and P. Ferrero and A. Franceschini and R. Gavazzi and J. Glenn and E. A. Gonzalez Solares and M. A. Gurwell and M. Halpern and E. Hatziminaoglou and A. Hyde and E. Ibar and A. Kovacs and M. Krips and R. E. Lupu and P. R. Maloney and P. Martinez-Navajas and H. Matsuhara and E. J. Murphy and B. J. Naylor and H. T. Nguyen and S. J. Oliver and A. Omont and M. J. Page and G. Petitpas and N. Rangwala and I. G. Roseboom and D. Scott and A. J. Smith and J. G. Staguhn and A. Streblyanska and A. P. Thomson and I. Valtchanov and M. Viero and L. Wang and M. Zemcov and J. Zmuidzinas},
journal= {arXiv preprint arXiv:1304.4256},
year = {2013}
}
Comments
35 pages, 19 figures, 5 tables, including Supplementary Information (version formatted by the authors). To appear in Nature. Under press embargo until 18:00 London time/13:00 US Eastern Time on 17 April 2013