English

Constraining the Structure of GRB Jets Through the Afterglow Light Curves

Astrophysics 2016-08-30 v1

Abstract

We investigate the effect that the structure of GRB jets has on the afterglow light curves for observers located at different viewing angles, θobs\theta_{obs}, from the jet symmetry axis. The largest uncertainty in the jet dynamics is the degree of lateral energy transfer. Thus, we use two simple models, that make opposite and extreme assumptions for this point, and calculate the light curves for an external density that is either homogeneous, or decreases as the square of the distance from the source. The Lorentz factor and kinetic energy per unit solid angle are initially taken to be power laws of the angle from the jet axis. We perform a qualitative comparison between the resulting light curves and afterglow observations. This constrains the jet structure, and poses problems for a `universal' jet model, where all GRB jets are assumed to be intrinsically identical, and differ only by our viewing angle, θobs\theta_{obs}.

Keywords

Cite

@article{arxiv.astro-ph/0212540,
  title  = {Constraining the Structure of GRB Jets Through the Afterglow Light Curves},
  author = {Jonathan Granot and Pawan Kumar},
  journal= {arXiv preprint arXiv:astro-ph/0212540},
  year   = {2016}
}

Comments

19 pages, 7 figures; submitted to ApJ in November 2002