Decay of the GRB 990123 optical afterglow: Implications for the fireball model

DOI: 
10.1126/science.283.5410.2069
Publication date: 
26/03/1999
Main author: 
Castro-Tirado A.J.
IAA authors: 
Castro-Tirado A.J.
Authors: 
Castro-Tirado A.J., Zapatero-Osorio M.R., Caon N., Cairós L.M., Hjorth J., Pedersen H., Andersen M.I., Gorosabel J., Bartolini C., Guarnieri A., Piccioni A., Frontera F., Masetti N., Palazzi E., Pian E., Greiner J., Hudec R., Sagar R., Pandey A.K., Mohan V., Yadav R.K.S., Nilakshi, Björnsson G., Jakobsson P., Burud I., Courbin F., Valentini G., Piersimoni A., Aceituno J., Montoya L.M., Pedraz S., Gredel R., Claver C.F., Rector T.A., Rhoads J.E., Walter F., Ott J., Hippelein H., Sánchez-Béjar V., Gutiérrez C., Oscoz A., Zhu J., Chen J., Zhang H., Wei J., Zhou A., Guziy S., Shlyapnikov A., Heise J., Costa E., Feroci M., Piro L.
Journal: 
Science
Publication type: 
Article
Volume: 
283
Pages: 
2069-2073
Number: 
Abstract: 
Broad-band (ultraviolet to near-infrared) observations of the intense gamma ray burst GRB 990123 started ~8.5 hours after the event and continued until 18 February 1999. When combined with other data, in particular from the Robotic Telescope and Transient Source Experiment (ROTSE) and the Hubble Space Telescope (HST), evidence emerges for a smoothly declining light curve, suggesting some color dependence that could be related to a cooling break passing the ultraviolet-optical band at about 1 day after the high-energy event. The steeper decline rate seen after 1.5 to 2 days may be evidence for a collimated jet pointing toward the observer.
Database: 
WOK
SCOPUS
Keywords: