Ciência-IUL
Publications
Publication Detailed Description
Journal Title
Astrophysical Journal Letters
Year (definitive publication)
2009
Language
English
Country
United States of America
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Abstract
Ab initio numerical study of collisionless shocks in electron-ion unmagnetized plasmas is performed with fully relativistic particle in cell simulations. The main properties of the shock are shown, focusing on the implications for particle acceleration. Results from previous works with a distinct numerical framework are recovered, including the shock structure and the overall acceleration features. Particle tracking is then used to analyze in detail the particle dynamics and the acceleration process. We observe an energy growth in time that can be reproduced by a Fermi-like mechanism with a reduced number of scatterings, in which the time between collisions increases as the particle gains energy, and the average acceleration efficiency is not ideal. The in depth analysis of the underlying physics is relevant to understanding the generation of high-energy cosmic rays, the impact on the astrophysical shock dynamics, and the consequent emission of radiation.
Acknowledgements
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Keywords
Acceleration of particles,Gamma rays: bursts,Methods: numerical
Fields of Science and Technology Classification
- Physical Sciences - Natural Sciences
Funding Records
Funding Reference | Funding Entity |
---|---|
SFRH/BD/35749/2007 | Fundação para a Ciência e a Tecnologia |
PTDC/FIS/66823/2006 | Fundação para a Ciência e a Tecnologia |