Abstract
We have investigated how kinetic instabilities such as the Weibel
instability (WI), the mushroom instability (MI), and the kinetic
Kelvin–Helmholtz instability (kKHI) are excited in jets without and with
a toroidal magnetic field, and how such instabilities contribute to
particle acceleration. In this work, we use a new jet injection scheme,
where an electric current is self-consistently generated at the jet
orifice by the jet particles, which produce the toroidal magnetic field.
We perform five different simulations for a sufficiently long time to
examine the non-linear effects of the jet evolution. We inject
unmagnetized e± and e−– p+ (mp/me = 1836), as well as magnetized e± and e−– i+ (mi/me
= 4) jets with a top-hat jet density profile into an unmagnetized
ambient plasmas of the same species. We show that WI, MI, and kKHI
excited at the linear stage, generate a non-oscillatory x-component of the electric field accelerating, and decelerating electrons. We find that the two different jet compositions (e± and e−– i+)
display different instability modes, respectively. Moreover, the
magnetic field in the non-linear stage generated by different
instabilities is dissipated and reorganized into new topologies. A 3D
magnetic field topology depiction indicates possible reconnection sites
in the non-linear stage, where the particles are significantly
accelerated by the dissipation of the magnetic field associated to a
possible reconnection event.
Original language | English |
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Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 519 |
Issue number | 4 |
Pages (from-to) | 5410-5426 |
ISSN | 0035-8711 |
DOIs | |
Publication status | Published - 2023 |
Keywords
- Acceleration of particles
- Instabilities
- Relativistic processes
- Shock waves
- Galaxies: jets