Program: GS-2007A-Q-3

Though the emergent diversity in the progenitors of Gamma-ray Bursts (GRBs) is of pressing interest, the elusive nature of the phenomena makes the detailed study of the physical origin of the trigger particularly challenging. The Swift satellite, now more than one year into operation, has revolutionized the field by providing unprecedented real-time localization rates and accuracies of the full suite of burst subclasses: long-duration and short-duration GRBs and X-ray Flashes. The rapid localizations allow us to go beyond a simple redshift measurement for each burst to conduct extensive imaging and spectroscopic observations. In addition, the GRB afterglows prove to be a versatile and unique astrophysical probe for studying the ISM of distant galaxies, the IGM at z>2, and into the reionization epoch. Here we propose a wide-reaching Target-of-Opportunity program on the Gemini Telescopes --- using both the imaging and spectroscopic capabilities at infrared and optical wavelengths --- in concert with our existing rapid response programs on small-aperture facilities for a comprehensive study of new Swift bursts in the 2007A semester.