Gamma-Ray Bursts and Afterglow
The origin of GRBs have been a mystery for almost 30 years. Their sources
emit huge amount of energy on short time scales and the emission
involve extreme relativistic motion with bulk Lorentz factor of at least
In the last two year, X-ray, optical, IR, and radio afterglow
was detected, lasting up to months and even years after the GRB.
We review the theory for the g-rays emission and the afterglow and
show that these are well supported by the observations.
A recent detection of prompt optical emission, during the GRB event
of January 23rd, well agrees with theoretical predictions and farther
constrain the free parameters of the models. We discuss the evidence that
some of these bursts are beamed, and show that future polarization
measurement could provide unique tests to that picture.
File translated from TEX by TTH, version 2.32.
On 23 Jul 1999, 15:33.