Optical and NIR Observations of the Afterglow of GRB 020813
Astrophysics
2009-11-07 v2
Abstract
We present optical and near-infrared (NIR) photometry of the bright afterglow of GRB 020813. Our data span from 3 hours to 4 days after the GRB event. A rather sharp achromatic break is present in the light curve, 14 hours after the trigger. In the framework of jetted fireballs, this break corresponds to a jet half opening angle of (1.9 +- 0.2) deg, the smallest value ever inferred for a GRB. We discuss our results in the framework of currently available models, and find that they have problems in explaining the joint temporal and spectral properties, and in particular the slow decay before the break.
Cite
@article{arxiv.astro-ph/0304171,
title = {Optical and NIR Observations of the Afterglow of GRB 020813},
author = {S. Covino and D. Malesani and F. Tavecchio and L. A. Antonelli and A. Arkharov and A. Di Paola and D. Fugazza and G. Ghisellini and V. Larionov and D. Lazzati and F. Mannucci and N. Masetti and R. Barrena and S. Benetti and A. J. Castro-Tirado and S. Di Serego Alighieri and F. Fiore and F. Frontera and A. Fruchter and F. Ghinassi and M. Gladders and P. B. Hall and G. L. Israel and S. Klose and A. Magazzu' and E. Palazzi and M. Pedani and E. Pian and P. Romano and M. Stefanon and L. Stella},
journal= {arXiv preprint arXiv:astro-ph/0304171},
year = {2009}
}
Comments
5 pages, 4 (color) figures; minor changes introduced; published in A&A Letters; includes aa.cls and txfonts.sty