A POPULATION OF MASSIVE, LUMINOUS GALAXIES HOSTING HEAVILY DUST-OBSCURED GAMMA-RAY BURSTS: IMPLICATIONS FOR THE USE OF GRBs AS TRACERS OF COSMIC STAR FORMATION

Support for this work was provided by NASA through Hubble Fellowship grant HST-HF-51296.01-A awarded by the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., for NASA, under contract NAS 5-26555. The Dark Cosmology Centre is supported by the Danish National Science Foundation. J.P.U.F. and B.M.J. acknowledge support from ERC-StG grant EGGS-278202. T.K. acknowledges support by the European Commission under the Marie Curie Intra-European Fellowship Programme in FP7. A.V.F. and his group acknowledge generous financial assistance from Gary & Cynthia Bengier, the Richard & Rhoda Goldman Fund, the Christopher R. Redlich Fund, NASA/Swift grants NNX10AI21G and NNX12AD73G, the TABASGO Foundation, and NSF grant AST-1211916. J.X.P. acknowledges support from NASA/Swift grants NNX07AE94G and NNX12AD74G. This work is based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs GO-10908, 11343, 11840, 12307, 12378, 12764, and 12949. Support for HST programs GO-11840, GO-12378, and GO-12674 was provided by NASA through a grant from STScI, which is operated by AURA, Inc., under NASA contract NAS 5-26555. The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA; the Observatory was made possible by the generous financial support of the W. M. Keck Foundation. We wish to extend special thanks to those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. P