Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-05-07
Astrophys.J. 595 (2003) 555-563
Astronomy and Astrophysics
Astrophysics
ApJ, in press, Sept. 20, 2003 (figures with better resolution: http://gammaray.nsstc.nasa.gov/~nishikawa/apjweib.pdf)
Scientific paper
10.1086/377260
Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet front propagating through an ambient plasma with and without initial magnetic fields. We find only small differences in the results between no ambient and weak ambient magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates particles perpendicular and parallel to the jet propagation direction. While some Fermi acceleration may occur at the jet front, the majority of electron acceleration takes place behind the jet front and cannot be characterized as Fermi acceleration. The simulation results show that this instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields, which contribute to the electron's transverse deflection behind the jet head. The ``jitter'' radiation (Medvedev 2000) from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.
Fishman Gerald J.
Hardee Philip
Nishikawa Ken-Ichi
Preece Rob
Richardson Gareth
No associations
LandOfFree
Particle Acceleration in Relativistic Jets due to Weibel Instability 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 Particle Acceleration in Relativistic Jets due to Weibel Instability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Particle Acceleration in Relativistic Jets due to Weibel Instability will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-596029