تقرير
Study of time evolution of the bend-over energy in the energetic particle spectrum at a parallel shock
| العنوان: | Study of time evolution of the bend-over energy in the energetic particle spectrum at a parallel shock |
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| المؤلفون: | Kong, F. -J., Qin, G., Wu, S. -S., Zhang, L. -H., Wang, H. -N., Chen, T., Sun, P. |
| سنة النشر: | 2017 |
| المجموعة: | Astrophysics Physics (Other) |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, Physics - Space Physics |
| الوصف: | Shock acceleration is considered one of the most important mechanisms for the acceleration of astrophysical energetic particles. In this work, we calculate the trajectories of a large number of test charged particles accurately in a parallel shock with magnetic turbulence. We investigate the time evolution of the accelerated-particle energy spectrum in the downstream of the shock in order to understand the acceleration mechanism of energetic particles. From simulation results we obtain power-law energy spectra with a bend-over energy, $E_0$, increasing with time. With the particle mean acceleration time and mean momentum change during each cycle of the shock crossing from diffusive shock acceleration model (following Drury), a time-dependent differential equation for the maximum energy, $E_{acc}$, of particles accelerated at the shock, can be approximately obtained. We assume the theoretical bend-over energy as $E_{acc}$. It is found that the bend-over energy from simulations agrees well with the theoretical bend-over energy using the non-linear diffusion theory, NLGCE-F, in contrast to that using the classic quasi-linear theory (QLT). Comment: 22 pages, 6 figures and 2 table |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/1702.04647 |
| رقم الأكسشن: | edsarx.1702.04647 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |