Volume 437, Number 2, July II 2005
|Page(s)||L23 - L25|
|Published online||21 June 2005|
Letter to the Editor
Early BVRI imaging and the discovery of the optical afterglow of GRB 041218
Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan e-mail: firstname.lastname@example.org
Accepted: 3 May 2005
We report early imaging of the INTEGRAL GRB 041218. The observation started 129 s after the burst and a sequence of exposures in V, Rc, Ic, and B bands were repeated. The optical afterglow is detected in Rc and bands while it was not detected in B and V. We find that the early afterglow deviates from a single power law decay and identify two characteristic timescales (breaks). Such breaks are theoretically expected from synchrotron cooling in the relativistic fireball (Sari et al. 1998, ApJ, 497, L17) and we crudely constrain the physical condition of the relativistic shock.
Key words: gamma rays: bursts
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.