Speaker
Description
The properties of relativistic jets, their interaction with the ambient environment, and particle acceleration due to kinetic instabilities are studied self-consistently with Particle-in-Cell simulations. An important key issue is how a toroidal magnetic field affects the evolution of an electron-positron and electron-proton jets, how kinetic instabilities such as the Weibel instability (WI), the mushroom instability (MI) and the kinetic Kelvin-Helmholtz instability (kKHI) are excited with and without the toroidal magnetic field, and how such instabilities contribute to particle acceleration. We show that WI, MI and kKHI excited at the linear stage, generate a quasi-steady 𝑥-component of electric field which accelerates and decelerates electrons. In this report, we use a new jet injection scheme where an electric current is self-consistently generated at the jet orifice by the jet particles. We inject both electron-positron and electron-proton jets with a toroidal magnetic field (with a top-hat and Lorentzian jet density profiles) and for a sufficiently long time in order to examine the non-linear effects of the jet evolution. We find that different jet compositions present different strongly excited instability modes. The magnetic field in the non-linear stage generated by different instabilities becomes dissipated and reorganized into a new topology at the nonlinear stage. The 3-dimensional magnetic field topology indicates possible reconnection locations and the accelerated particles are significantly accelerated in the non-linear stage by the dissipation of the magnetic field and/or reconnection. This study will shed further light on the nature of astrophysical relativistic magnetized jet phenomena.
| Length of presentation requested | Oral presentation: 17 min + 3 min questions |
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| Please select between one and three keywords related to your abstract | Cosmic Rays |
