Detailed afterglow modelling and host galaxy properties of the dark GRB 111215A

AJvdH and RAMJW acknowledge support from the European Research Council via Advanced Investigator Grant no. 247295. KW acknowledges support from the Science and Technology Facilities Council (STFC). Support for DAP was provided by NASA through Hubble Fellowship grant HSTHF-51296.01-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. RLCS is supported by a Royal Society Fellowship. PAC acknowledges support from Australian Research Council grant DP120102393. The Westerbork Synthesis Radio Telescope is operated by Netherlands Institute for Radio Astronomy (ASTRON) with support from the Netherlands Foundation for Scientific Research. The Arcminute Microkelvin Imager arrays are supported by the University of Cambridge and the STFC. The William Herschel Telescope and Nordic Optical Telescope are operated on the island of La Palma by the Isaac Newton Group and Nordic Optical Telescope Scientific Association, respectively, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration (NASA); the Observatory was made possible by the generous financial support of the W.M. Keck Foundation. 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; Spitzer observations were undertaken as part of large program 90062. Some observations were made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in A