Numerical simulation-based jet model fits to GRB light curves

Author: Binbin Zhang

Abstract: We address the open problem of "missing" jet breaks in Swift XRT afterglows by fitting afterglows of 34 GRBs with detailed Swift data and late-time Chandra observations to jet models obtained from high resolution hydrodynamics simulations (van Eerten and MacFadyen 2012). These detailed models allow us to determine GRB jet parameters, including jet break times, jet opening angle, observer angle, shock-accelerated electron distribution and GRB energies, with higher fidelity than allowed by previous afterglow fits based on analytic approximations to the jet evolution. We will present preliminary results from this work.