Program: GN-2012A-Q-39

Rapid observations of gamma-ray burst afterglows are critical to probing their exotic physics and using them as probes of the Universe. Gemini-N observations led to discovery of two of the highest-redshift objects known, GRBs 090423 at z=8.2 and 090429B at z~9.4, in campaigns led by our merged collaboration. Our approach is to both study individual key events and build up statistical samples. Primary goals remain (1) To observe GRBs at z>6, where they provide luminous probes of star-forming galaxies and the evolving intergalactic medium throughout the reionization era, (2) To detect afterglows and measure redshifts for short-duration bursts, whose nature remains enigmatic, (3) To construct a more complete redshift sample of GRBs and constrain the evolution of the mass-metallicity relation using their host galaxies, and (4) To identify and observe bursts of particular interest including low-redshift GRB-supernovae, oddball events like the tidal disruption event GRB110328A/SwiftJ1644+57, and Fermi-LAT detected bursts. Gemini is a cornerstone facility of global GRB research, and we will continue to use it judiciously in combination with a large network of small telescopes and ground- and space-based facilities.