Modeling the Radio and Optical/NIR Afterglows of GRB 980703: a Numerical Study.

GRB 980703 has extensive available multiband afterglow data. Especially, its radio afterglows were very bright and monitored until more than 1000 days after the trigger time. This makes GRB 980703 a precious sample in GRB research. We calculate the radio and optical/NIR afterglows of GRB 980703 numerically, by using a set of generic dynamical equations. It is found that the observations consist with the theoretical expectation of the standard fireball model well. Our result suggests that the jet opening angle is ∼13°, the number density of the surrounding medium is ∼30 cm-3, and the isotropic equivalent kinetic energy of the explosion is ∼3.8×1052 ergs. [ABSTRACT FROM AUTHOR]