The X - ray , optical and radio evolution of the GRB 030329 afterglow and the associated SN 2003 dh

Extensive X-ray, optical and radio observations of the bright afterglow of the Gamma Ray Burst GRB 030329 are used to construct the spectral and temporal history of the event. The data are fitted using the standard fireball shock model to provide estimates of the initial energy, ε = 6.8×10 52 ergs sr −1 , the density of the ambient medium, n 0 = 1 cm −3 , the electron and magnetic energy density fractions, ǫ e = 0.24 & ǫ B = 0.0017, the power law index of the relativistic electron spectrum, p = 2.25, and the opening angle of the jet, θ j = 3 degrees. Deviations from the standard model seen in the optical and radio are most likely attributable to the concurrent hypernova SN2003dh. Peaks at 0.23 and 1.7 days in the R-band possibly represent the first complete light curve observed for any supernova. If so, the supernova occurred within a few hours of the GRB.