| In the last three years we have learned that Gamma-Ray Bursts (GRB) are the most powerful photon emitters in the Universe, allowing us to study the extreme physical conditions in the explosion and to use them to explore the very early Universe. I propose a research program for observations of GRB afterglows and their host galaxies in order to: (i) obtain information on the origin of GRBs, (ii) study their spatial distribution in the Universe, (iii) investigate the possibility of different populations of GRBS, (iv) study the physics of the ultra-relativistic GRB phenomenon, and finally (v) use GRBS as probes of star and galaxy formation in the very early Universe (redshift z > 5). The means to pursue this rigorous program are provided by: (i) the "Vernieuwingsimpuls" grant, which will allow me to build an internationally leading group at the University of Amsterdam; (ii) the availability of an extensive global network of telescopes, covering the radio, mm, optical, infrared X-ray and gamma-ray passbands; (iii) my personal collaborations with leading theorists and observers, and (iv) the imminent launch of the NASA missions HETE-II (this year) and SWIFT MIDEX (2003) which will for the first time allow rapid follow-up (within minutes) of GRB localizations, and follow-up of short-duration GRBS (heretofore undetected at other wavelengths). These missions will provide the unique possibility of detecting GRBS out to the redshifts at which the very first stars were formed corresponding to the first 2% of the age of the Universe, allowing us to derive important information about the physical state of the Universe at this very early epoch. |
