Optical and NIR observations of the afterglow of GRB 020813 | Instituto de Astrofísica de Andalucía

DOI:

Publication date:

01/01/2003

Main author:

Covino S.

IAA authors:

Castro-Tirado, A.J.

Authors:

Covino S., Malesani D., Tavecchio F., Antonelli L.A., Arkharov A., Di Paola A., Fugazza D., Ghisellini G., Larionov V., Lazzati D., Mannucci F., Masetti N., Barrena R., Benetti S., Castro-Tirado A.J., Di Serego Alighieri S., Fiore F., Frontera F., Fruchter A., Ghinassi F., Gladders M., Hall P.B., Israel G.L., Klose S., Magazzù A., Palazzi E., Pedani M., Pian E., Romano P., Stefanon M., Stella L.

Journal:

Astronomy and Astrophysics

Publication type:

Letter

Volume:

404

Pages:

L5-L9

Number:

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°, 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.

Database:

SCOPUS

Keywords:

Gamma rays: bursts; Radiation mechanisms: non-thermal