Numerical simulations of gamma-ray burst afterglows: energy injections and afterglow fitting
by
DrGudlaugur Johannesson(Science Institute, University of Iceland)
→
Europe/Stockholm
Nordita Seminar Room
Nordita Seminar Room
Description
The standard afterglow fireball model is revised and extended to include
arbitrary energy injection. Special attention is given to the emission
properties of the fireball and a method to fit the model to afterglow
observation is introduced. We also explore the consequences of introducing a
variable external density profile, chosen to represent the surroundings of
massive stars, currently believed to be the origin of long gamma-ray bursts.
We show that energy injections and complex density structures can naturally
explain the complexities sometimes observed in afterglow light curves.
The commonly used method of fitting afterglow light curves with broken power
laws is also explored. This is achieved by simulating a large population of
afterglows with our model and fitting them with a broken power-law. The
resulting parameters are then compared to the known model parameters. We
find that the parameter uncertainties are greater than statistically
estimated from the fitting parameters.
