Program: GS-2022B-Q-102

James Webb Space Telescope will soon begin explorating the first 600 million years of the Universe history. Identify the first stars and galaxies represent the ultimate frontier of modern astronomy. However, this epoch is challenging to probe due to the paucity and faintness of these light sources. Long-duration gamma-ray bursts (GRBs), thanks to their intrinsic brightness, act as beacons that illuminate this critical epoch. The simple power law synchrotron spectra of GRB afterglows allow measurements ranging from the properties of the intergalactic medium (IGM) and metal enrichment of the Universe, to the dynamics of the interstellar medium of high-redshift galaxies. The localization of the first GRBs at z~6, provided accurate constraints on the neutral H fraction of the IGM. Here we aim to identify more GRBs at z > 6 to improve our estimates of the neutral H through afterglow absorption spectroscopy, and to measure the gas phase metallicity of galaxies during the reionization epoch. This program will provide a direct search for explosions from the first stars, while the associated hosts will be the most promising, spectroscopically confirmed high-redshift galaxy targets for JWST in the epoch of reionization.