REM observations of GRB 060418: the fireball Lorentz factor determination
arXiv:astro-ph/0701688 · doi:10.1393/ncb/i2007-10333-7
Abstract
We measured the fireball Lorentz factor of GRB 060418 by the direct observation of the onset of the NIR afterglow carried with the REM telescope. We found a value of about 400.
arXiv comment2 pages, 1 eps figure. Proceedings of the "Swift and GRBs: Unveiling the Relativistic Universe" meeting, Venice, June 5-9, 2006, to be published by "Il Nuovo Cimento"