NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Particle Acceleration, Magnetic Field Generation and Associated Emission in Collisionless Relativistic JetsNonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), gamma-ray bursts (GRBs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations using injected relativistic electron-ion (electro-positron) jets show that acceleration occurs within the downstream jet. Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The "jitter" radiation 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.
Document ID
20080013343
Document Type
Conference Paper
Authors
Nishikawa, K. I.
Ramirez-Ruiz, E.
Hardee, P.
Mizuno, Y.
Fishman. G. J.
Date Acquired
August 24, 2013
Publication Date
November 7, 2007
Subject Category
Astrophysics
Meeting Information
Seventh European Workshop on Collisionless Shocks(Paris)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.