NSF East Asia and Pacific Summer Institute (EAPSI) for FY 2013 in Japan

Warren Donald C, Raleigh NC

Investigators

Abstract

This action funds Donald Warren of North Carolina State University to conduct a research project in the Math and Physical Sciences during the summer of 2013 at RIKEN in Tokyo. The project title is "Simulating the Early X-Ray Afterglow in Gamma-Ray Bursts." The host scientist is Shigehiro Nagataki. The early X-ray afterglows of gamma-ray bursts (GRBs) are important for understanding these events and their impact on cosmology. This project models the acceleration of cosmic rays, and emission from that population, using a Monte Carlo code that simulates particle interactions with a modified, ultra-relativistic, collisionless shock. This study focuses on the relation between observed parameters of X-ray afterglows (e.g. the total energy output, and the power law indices of energy flux in both wavelength and time), the characteristics of the shocks that generate the afterglows (e.g. flow speed, acceleration efficiency, or magnetic field strength), and the nature of the GRB progenitors (e.g. stellar type and size, or properties of the central engine powering the GRB). In addition, this project is obtaining spectral information about the population of cosmic rays, which can be compared against observations at Earth to see if GRBs and their afterglows are viable candidates for the source of the highest energy cosmic rays. Broader impacts of an EAPSI fellowship include providing the Fellow a first-hand research experience outside the U.S.; an introduction to the science, science policy, and scientific infrastructure of the respective location; and an orientation to the society, culture and language. These activities meet the NSF goal to educate for international collaborations early in the career of its scientists, engineers, and educators, thus ensuring a globally aware U.S. scientific workforce.