Prospects for ultra-high-energy particle acceleration at relativistic shocks
Jul 25, 2023
8 pages
Published in:
- PoS ICRC2023 (2023) 193
Contribution to:
- , 193
- ICRC2023
- Published: Jul 25, 2023
DOI:
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Abstract: (SISSA)
Using test-particle Monte-Carlo simulations, we revisit the particle acceleration at ultra-relativistic shocks. The produced particle spectra are studied on the conditions of two regular field configurations: (i) uniform upstream field perpendicular to the shock normal, and (ii) upstream field with a cylindrical geometry. For uniform field configurations, particles could keep being accelerated until becoming magnetized on either side of the shock, which contradicts the widely-held belief that the maximum energy is constrained by the downstream magnetized limit. The corresponding steady-state particle distribution satisfies , similar to that predicted for the parallel shock case. For the cylindrical field configuration, the acceleration efficiency depends on the charge of the particles. Particles with a favorable charge will experience a curvature drift motion parallel to the shock velocity and hence increases the probability of downstream particles to cross the shock. Considering the non-resonant scattering model, these particles can only escape when reaching the confinement limit of the system size, and the accelerated spectrum could become even harder.- particle: acceleration
- particle: charge
- numerical calculations: Monte Carlo
- particle: spectrum
- acceleration: efficiency
- scattering: model
- geometry
- confinement
- UHE
References(6)
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