Document Type

Article

Publication Date

8-22-2009

Publication Title

The Astrophysical Journal Letters

Volume

698

Issue

1

Publisher

The American Astronomical Society

Abstract

Plasma instabilities (e.g., Buneman, Weibel and other two-stream instabilities) excited in collision-less shocks are responsible for particle (electron, positron, and ion) acceleration. Using a new 3-D relativistic particle-in-cell code, we have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic electron-positron jet propagating into an unmagnetized electron-positron plasma. The simulation has been performed using a long simulation system in order to study the nonlinear stages of the Weibel instability, the particle acceleration mechanism, and the shock structure. Cold jet electrons are thermalized and slowed while the ambient electrons are swept up to create a partially developed hydrodynamic (HD) like shock structure. In the leading shock, electron density increases by a factor of 3.5 in the simulation frame. Strong electromagnetic fields are generated in the trailing shock and provide an emission site. We discuss the possible implication of our simulation results within the AGN and GRB context.

Comments

This manuscript has been published in the Astrophysical Journal Letters. Please find the published version here (note that a subscription is necessary to access this version):

http://iopscience.iop.org/1538-4357/698/1/L10/article?fromSearchPage=true

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