1. Radiation from shock-accelerated particles
- Author
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Philip E. Hardee, J. T. Frederiksen, Yosuke Mizuno, Ken-Ichi Nishikawa, M. Pohl, Dieter H. Hartmann, Gerald J. Fishman, Jacek Niemiec, Bing Zhang, Mikhail V. Medvedev, Aake Nordlund, Helene Sol, E. J. Choi, and K. W. Min
- Subjects
Electromagnetic field ,Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Electron ,Plasma ,Radiation ,Magnetic field ,Particle acceleration ,Lorentz factor ,symbols.namesake ,Deflection (physics) ,Physics::Plasma Physics ,Physics::Space Physics ,symbols ,Atomic physics ,Astrophysics::Galaxy Astrophysics - Abstract
Plasma instabilities excited in collisionless shocks are responsible for particle acceleration, generation of magnetic fields , and associated radiation. We have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic jet propagating into an unmagnetized plasma. Cold jet electrons are thermalized and slowed while the ambient electrons are swept up to create a partially developed hydrodynamic-like shock structure. The shock structure depends on the composition of the jet and ambient plasma (electron-positron or electron-ions). Strong electromagnetic fields are generated in the reverse , jet shock and provide an emission site. These magnetic fields contribute to the electron's transverse deflection behind the shock. We have calculated, self-consistently, the radiation from electrons accelerated in the turbulent magnetic fields. We found that the synthetic spectra depend on the Lorentz factor of the jet, its thermal temperature and strength of the generated magnetic fields. The detailed properties of the radiation are important for understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jet shocks, and supernova remnants
- Published
- 2012
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