Kinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent Medium
Strong nonrelativistic shocks are known to accelerate particles up to relativistic energies. However, for diffusive shock acceleration, electrons must have a highly suprathermal energy, implying the need for very efficient preacceleration. Most published studies consider shocks propagating through h...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/ad04dc |
| _version_ | 1827585613572866048 |
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| author | Karol Fulat Artem Bohdan Gabriel Torralba Paz Martin Pohl |
| author_facet | Karol Fulat Artem Bohdan Gabriel Torralba Paz Martin Pohl |
| author_sort | Karol Fulat |
| collection | DOAJ |
| description | Strong nonrelativistic shocks are known to accelerate particles up to relativistic energies. However, for diffusive shock acceleration, electrons must have a highly suprathermal energy, implying the need for very efficient preacceleration. Most published studies consider shocks propagating through homogeneous plasma, which is an unrealistic assumption for astrophysical environments. Using 2D3V particle-in-cell simulations, we investigate electron acceleration and heating processes at nonrelativistic high-Mach-number shocks in electron-ion plasma with a turbulent upstream medium. For this purpose, slabs of plasma with compressive turbulence are simulated separately and then inserted into shock simulations, which require matching of the plasma slabs at the interface. Using a novel procedure of matching electromagnetic fields and currents, we perform simulations of perpendicular shocks setting different intensities of density fluctuations (≲10%) in the upstream region. The new simulation technique provides a framework for studying shocks propagating in turbulent media. We explore the impact of the fluctuations on electron heating, the dynamics of upstream electrons, and the driving of plasma instabilities. Our results indicate that while the presence of turbulence enhances variations in the upstream magnetic field, their levels remain too low to significantly influence the behavior of electrons at perpendicular shocks. |
| first_indexed | 2024-03-08T23:49:08Z |
| format | Article |
| id | doaj.art-b696107dddd04b068688ba6a68ff36c4 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T23:49:08Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-b696107dddd04b068688ba6a68ff36c42023-12-13T13:21:06ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01959211910.3847/1538-4357/ad04dcKinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent MediumKarol Fulat0https://orcid.org/0000-0001-6002-6091Artem Bohdan1https://orcid.org/0000-0002-5680-0766Gabriel Torralba Paz2https://orcid.org/0000-0003-1699-5770Martin Pohl3https://orcid.org/0000-0001-7861-1707Institute of Physics and Astronomy, University of Potsdam , D-14476 Potsdam, Germany ; karol.fulat@uni-potsdam.deMax-Planck-Institut für Plasmaphysik , Boltzmannstr. 2, D-85748 Garching, Germany; Excellence Cluster ORIGINS , Boltzmannstr. 2, D-85748 Garching, GermanyInstitute of Nuclear Physics PAN , Radzikowskiego 152, 31-342, Kraków, PolandInstitute of Physics and Astronomy, University of Potsdam , D-14476 Potsdam, Germany ; karol.fulat@uni-potsdam.de; Deutsches Elektronen-Synchrotron DESY , Platanenallee 6, D-15738 Zeuthen, GermanyStrong nonrelativistic shocks are known to accelerate particles up to relativistic energies. However, for diffusive shock acceleration, electrons must have a highly suprathermal energy, implying the need for very efficient preacceleration. Most published studies consider shocks propagating through homogeneous plasma, which is an unrealistic assumption for astrophysical environments. Using 2D3V particle-in-cell simulations, we investigate electron acceleration and heating processes at nonrelativistic high-Mach-number shocks in electron-ion plasma with a turbulent upstream medium. For this purpose, slabs of plasma with compressive turbulence are simulated separately and then inserted into shock simulations, which require matching of the plasma slabs at the interface. Using a novel procedure of matching electromagnetic fields and currents, we perform simulations of perpendicular shocks setting different intensities of density fluctuations (≲10%) in the upstream region. The new simulation technique provides a framework for studying shocks propagating in turbulent media. We explore the impact of the fluctuations on electron heating, the dynamics of upstream electrons, and the driving of plasma instabilities. Our results indicate that while the presence of turbulence enhances variations in the upstream magnetic field, their levels remain too low to significantly influence the behavior of electrons at perpendicular shocks.https://doi.org/10.3847/1538-4357/ad04dcShocksSupernova remnantsPlasma astrophysicsComputational methods |
| spellingShingle | Karol Fulat Artem Bohdan Gabriel Torralba Paz Martin Pohl Kinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent Medium The Astrophysical Journal Shocks Supernova remnants Plasma astrophysics Computational methods |
| title | Kinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent Medium |
| title_full | Kinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent Medium |
| title_fullStr | Kinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent Medium |
| title_full_unstemmed | Kinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent Medium |
| title_short | Kinetic Simulations of Nonrelativistic High-mach-number Perpendicular Shocks Propagating in a Turbulent Medium |
| title_sort | kinetic simulations of nonrelativistic high mach number perpendicular shocks propagating in a turbulent medium |
| topic | Shocks Supernova remnants Plasma astrophysics Computational methods |
| url | https://doi.org/10.3847/1538-4357/ad04dc |
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