Evidence of a Two-Component Jet in the Afterglow of GRB 070419A

TL;DR

This paper presents evidence for a two-component jet model to explain the complex afterglow behavior of GRB 070419A, involving a narrow and a wide jet with different opening angles and energy injections.

Contribution

It introduces a two-component jet model with specific jet angles and energy injections to explain the afterglow features of GRB 070419A.

Findings

A wide jet with an opening angle > 30-40 degrees causes late shallow decay.

A narrow jet with an opening angle of 2-4 degrees explains early power-law segments.

Late X-ray emission could originate from either jet component.

Abstract

A two-component jet model is proposed to explain the unusual afterglow of GRB 070419A. Regarding the optical light curve, a wide "jet" with an opening angle of > 30-40 degrees is assumed to produce the late shallow decay, while the three early power-law segments must be caused by a narrow jet with an opening angle of about 2-4 degrees. Additional energy injections to both components are required. Late X-ray emission may come from either the wide jet or the narrow one. If the latter is correct, the jets may run into an ISM environment and the temporal index of the late energy injection q may be about 0.65.