Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-07-30
Astronomy and Astrophysics
Astrophysics
ApJ in press, 13 pages, 9 figs
Scientific paper
10.1086/522072
We investigate here the effects of plasma instabilities driven by rapid electron/positron pair cascades, which arise in the environment of GRB sources as a result of back-scattering of a seed fraction of the original spectrum. The injection of electron/positron pairs induces strong streaming motions in the ambient medium. One therefore expects the pair-enriched medium ahead of the forward shock to be strongly sheared on length scales comparable to the radiation front thickness. Using three-dimensional particle-in-cell simulations, we show that plasma instabilities driven by these streaming electron/positron pairs are responsible for the excitation of near-equipartition, turbulent magnetic fields. Our results reveal the importance of the electromagnetic filamentation instability in ensuring an effective coupling between electron/positron pairs and ions, and may help explain the origin of large upstream fields in GRB shocks.
Hededal Christian Busk
Nishikawa Ken-Ichi
Ramirez-Ruiz Enrico
No associations
LandOfFree
Electron-Positron Pair Loading and the Origin of the Upstream Magnetic Field in GRB Shocks 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 Electron-Positron Pair Loading and the Origin of the Upstream Magnetic Field in GRB Shocks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electron-Positron Pair Loading and the Origin of the Upstream Magnetic Field in GRB Shocks will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-359381