| Auteurs | E. Rol, R.A.M.J. Wijers, J.U. Fynbo, J. Hjorth, J. Gorosabel, M.P. Egholm, J.M. Castro Ceron, A.J. Castro-Tirado, L. Kaper, N. Masetti, E. Palazzi, E. Pian, N. Tanvir, P.M. Vreeswijk, C. Kouveliotou, P. Moller, H. Pedersen, A.S. Fruchter, J. Rhoads, I. Burud, M.I. de Salamanca, E.P.J. van den Heuvel | | Titel | Variable polarization in the optical afterglow of GRB 021004 |
| Tijdschrift | Astronomy and Astrophysics |
| Jaargang | 405 |
| Jaar | 2003 |
| Pagina's | L23-L27 |
| ISSN | 00046361 |
| Faculteit | Faculteit der Natuurwetenschappen, Wiskunde en Informatica |
| Instituut/afd. | FNWI: Astronomical Institute Anton Pannekoek (IAP) |
| Trefwoorden | Gamma ray bursts; Gamma ray polarization |
| Samenvatting | We present polarimetric observations of the afterglow of gamma-ray burst (GRB) 021004, obtained with the Nordic Optical Telescope (NOT) and the Very Large Telescope (VLT) between 8 and 17 hours after the burst. Comparison among the observations shows a 45 degree change in the position angle from 9 hours after the burst to 16 hours after the burst, and comparison with published data from later epochs even shows a 90 degree change between 9 and 89 hours after the burst. The degree of linear polarization shows a marginal change, but is also consistent with being constant in time. In the context of currently available models for changes in the polarization of GRBs, a homogeneous jet with an early break time of tb ~ 1 day provides a good explanation of our data. The break time is a factor 2 to 6 earlier than has been found from the analysis of the optical light curve. The change in the position angle of the polarization rules out a structured jet model for the GRB.
Based on observations made with the Nordic Optical Telescope; based on observations collected at the European Southern Observatory, Chile, by GRACE (Gamma-Ray Burst Afterglow Collaboration at ESO), under programme 70.D-0523(A). |
| Opmerkingen | cop. 2003 EDP sciences |
| Soort document | Artikel |
| Download bestand | |
| Document finder |
|
Gebruik dit adres om naar deze pagina te linken: http://dare.uva.nl/record/119208
Vraag/opmerking over dit recordMail aan een collega
Toevoegen aan bewaarset
|