Program: GS-2006A-Q-11

Long-duration gamma-rays bursts are enormously luminous and hence potentially extremely important probes of the early universe. They act as beacons for absorption studies of the IGM and their own host galaxies during the era of reionization, and, being associated with the deaths of massive stars, trace global star formation at this early time. Members of our collaboration have recently been involved in the discovery of GRBs at (record breaking) redshifts z=5.3 and z=6.3, and here propose to systematically search for and study further GRBs and their afterglows at z>~5. In addition, our candidate selection may also reveal a population of highly reddened afterglows, hitherto rare amongst observed GRBs, which are likely to provide important clues to star formation in dense galactic environments. Gemini is crucial to this endeavour, providing the nIR spectroscopy from which we will determine redshifts and study the physical conditions along the line of sight.