Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-01-24
Mon.Not.Roy.Astron.Soc.Lett. 369 (2006) L5-L8
Astronomy and Astrophysics
Astrophysics
9 pages, 2 figure, submitted to MNRAS Letters
Scientific paper
10.1111/j.1745-3933.2006.00161.x
The Swift X-Ray Telescope often observes a rapidly decaying X-ray emission stretching to as long as $ t \sim 10^3$ seconds after a conventional prompt phase. This component is most likely due to a prompt emission viewed at large observer angles $\theta > 1/\Gamma$, where $\theta\sim 0.1$ is a typical viewing angle of the jet and$\Gamma\geq 100$ is the Lorentz factor of the flow during the prompt phase. This can be used to estimate the prompt emission radii, $r_{em} \geq 2 t c/\theta^2 \sim 6 \times 10^{15}$ cm. These radii are much larger than is assumed within a framework of a fireball model. Such large emission radii can be reconciled with a fast variability, on time scales as short as milliseconds, if the emission is beamed in the bulk outflow frame, e.g. due to a random relativistic motion of ''fundamental emitters''. This may also offer a possible explanation for X-ray flares observed during early afterglows.
No associations
LandOfFree
Did Swift measure GRB prompt emission radii? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Did Swift measure GRB prompt emission radii?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Did Swift measure GRB prompt emission radii? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-404326