GRB 030329: three years of radio afterglow monitoring

TL;DR

This paper reports a three-year radio monitoring of GRB 030329, revealing key physical parameters of the burst and predicting LOFAR's capability to observe similar afterglows, enhancing understanding of relativistic blast waves.

Contribution

It provides detailed physical parameter estimates of GRB 030329's afterglow and demonstrates LOFAR's potential to observe similar events during their non-relativistic phase.

Findings

Determined burst energy and ambient medium density.

Modeled late-time radio light curve to predict LOFAR observations.

Confirmed jet nature of the relativistic outflow.

Abstract

Radio observations of gamma-ray burst (GRB) afterglows are essential for our understanding of the physics of relativistic blast waves, as they enable us to follow the evolution of GRB explosions much longer than the afterglows in any other wave band. We have performed a three-year monitoring campaign of GRB 030329 with the Westerbork Synthesis Radio Telescopes (WSRT) and the Giant Metrewave Radio Telescope (GMRT). Our observations, combined with observations at other wavelengths, have allowed us to determine the GRB blast wave physical parameters, such as the total burst energy and the ambient medium density, as well as investigate the jet nature of the relativistic outflow. Further, by modeling the late-time radio light curve of GRB 030329, we predict that the Low Frequency Array (LOFAR, 30-240 MHz) will be able to observe afterglows of similar GRBs, and constrain the physics of the blast wave during its non-relativistic phase.