Gamma-Ray Bursts as a Cosmic Window for Galaxy Evolution

Abstract

Present knowledge indicates that gamma-ray bursts are linked with massive stars. They will become invaluable probes of the early universe and galaxy formation. In the future, it will be possible to use gamma-ray bursts for two purposes: 1) to probe the history of massive star formation in the Universe by the rate of occurence of gamma-ray bursts, and 2) for the study of galaxy evolution at all lookback times by determining the nature of the galaxy hosts. Because gamma-rays are not attenuated by intervening dust and gas, the selection of the cosmic sites of massive star formation by this method is less affected by the biases associated with optical-uv surveys (e.g. UV-dropout techniques). Infrared and sub-millimeter follow up studies of the hosts of gamma-ray bursts may: 1) reveal a putative population of reddened ($R-K \geq 4$) galaxies at high redshifts, and 2) detect very massive stars (population III) formed at $z \geq$ 5.