PARTICLE ACCELERATION AND MAGNETIC FIELD GENERATION IN SHEAR-FLOWS ∗

We have investigated the generation of magnetic fields associated with velocity shear between an unmagnetized relativistic (core) jet and an unmagnetized sheath plasma by the kinetic Kelvin-Helmholtz instability for different mass ratios (mi/me = 1, 20, and 1836) and different jet Lorentz factors. We found that electron-positron cases have alternating magnetic fields instead of the DC magnetic fields found in electron-ion cases. We have also investigated particle acceleration and shock structure associated with an unmagnetized relativistic jet propagating into an unmagnetized plasma for electron-positron and electron-ion plasmas. Strong magnetic fields generated in the trailing shock lead to transverse deflection and acceleration of the electrons. We have self-consistently calculated the radiation from the electrons accelerated in the turbulent magnetic fields for different jet Lorentz factors. We find that the synthetic spectra depend on the bulk Lorentz factor of the jet, the jet temperature, and the strength of the magnetic fields generated in the shock.

[1]  M. Pohl,et al.  Magnetic Field Generation in a Jet-Sheath Plasma via the Kinetic Kelvin-Helmholtz Instability , 2013, 1307.2928.

[2]  A. Meli,et al.  Active galactic nuclei jets and multiple oblique shock acceleration: starved spectra , 2012, 1207.4397.

[3]  Markus Boettcher,et al.  MAGNETIC FIELD GENERATION AND PARTICLE ENERGIZATION AT RELATIVISTIC SHEAR BOUNDARIES IN COLLISIONLESS ELECTRON–POSITRON PLASMAS , 2011, 1111.3326.

[4]  S. F. Martins,et al.  LARGE-SCALE MAGNETIC FIELD GENERATION VIA THE KINETIC KELVIN–HELMHOLTZ INSTABILITY IN UNMAGNETIZED SCENARIOS , 2011, 1107.6037.

[5]  M. Pohl,et al.  Simulation of Relativistic Jets and Associated Self-consistent Radiation , 2011, 1111.3622.

[6]  A. Meli.  Numerical modeling of relativistic particle shock acceleration , 2011 .

[7]  P. Hardee,et al.  THREE-DIMENSIONAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF CURRENT-DRIVEN INSTABILITY WITH A SUB-ALFVÉNIC JET: TEMPORAL PROPERTIES , 2011, 1104.0549.

[8]  Mikhail V. Medvedev,et al.  RADIATION SPECTRAL SYNTHESIS OF RELATIVISTIC FILAMENTATION , 2010, 1003.1140.

[9]  M. Pohl,et al.  Radiation from Relativistic Shocks with Turbulent Magnetic Fields , 2009, 0906.5018.

[10]  D. Uzdensky,et al.  Fast TeV variability in blazars: jets in a jet , 2009, 0901.1877.

[11]  P. Hardee,et al.  Three-dimensional Relativistic Magnetohydrodynamic Simulations of Magnetized Spine-Sheath Relativistic Jets , 2007, astro-ph/0703190.

[12]  Particle Acceleration and Magnetic Field Generation in Electron-Positron Relativistic Shocks , 2004, astro-ph/0409702.

[13]  Bing Zhang,et al.  Gamma-Ray Bursts: Progress, Problems & Prospects , 2004 .

[14]  F. A. Harrison,et al.  A Study of the Afterglows of Four GRBs: Constraining the Explosion and Fireball Model , 2003, astro-ph/0307056.