Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2509.12150 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866908540030943232 |
|---|---|
| author | van Marle, Allard Jan |
| author_facet | van Marle, Allard Jan |
| contents | When supersonic plasma flows collide, many physical processes contribute to the morphology of the resulting shock. One of these processes is the acceleration of non-thermal ions, which will, eventually, reach relativistic speeds and become cosmic rays. This process is difficult to simulate in a computer model because it requires both macro-physics (the overall shape of the shock) and micro-physics (the interaction between individual particles and the magnetic field). The combined PIC-MHD method is one of several options to get around this problem. It is based on the assumption that a plasma can be described as a combination of a thermal gas, which can be accurately described as a fluid using grid-based magnetohydrodynamics (MHD) and a small non-thermal component which has to be described as individual particles using particle-in-cell (PIC). By combining aspects of both methods, we reduce the computational costs while maintaining the ability to trace the acceleration of individual particles. We apply this method to a variety of astrophysical shock configurations to investigate if, and how, they can contribute to the cosmic ray spectrum. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_12150 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Combining PIC and MHD to model particle acceleration in astrophysical shocks van Marle, Allard Jan High Energy Astrophysical Phenomena When supersonic plasma flows collide, many physical processes contribute to the morphology of the resulting shock. One of these processes is the acceleration of non-thermal ions, which will, eventually, reach relativistic speeds and become cosmic rays. This process is difficult to simulate in a computer model because it requires both macro-physics (the overall shape of the shock) and micro-physics (the interaction between individual particles and the magnetic field). The combined PIC-MHD method is one of several options to get around this problem. It is based on the assumption that a plasma can be described as a combination of a thermal gas, which can be accurately described as a fluid using grid-based magnetohydrodynamics (MHD) and a small non-thermal component which has to be described as individual particles using particle-in-cell (PIC). By combining aspects of both methods, we reduce the computational costs while maintaining the ability to trace the acceleration of individual particles. We apply this method to a variety of astrophysical shock configurations to investigate if, and how, they can contribute to the cosmic ray spectrum. |
| title | Combining PIC and MHD to model particle acceleration in astrophysical shocks |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2509.12150 |