TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKS
In supernova remnants, the nonlinear amplification of magnetic fields upstream of collisionless shocks is essential for the acceleration of cosmic rays to the energy of the "knee" at 1015.5 eV. A nonresonant instability driven by the cosmic ray current is thought to be responsible for this...
| Główni autorzy: | , , , |
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| Format: | Journal article |
| Język: | English |
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Institute of Physics Publishing
2009
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| _version_ | 1826283164648079360 |
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| author | Ohira, Y Reville, B Kirk, J Takahara, F |
| author_facet | Ohira, Y Reville, B Kirk, J Takahara, F |
| author_sort | Ohira, Y |
| collection | OXFORD |
| description | In supernova remnants, the nonlinear amplification of magnetic fields upstream of collisionless shocks is essential for the acceleration of cosmic rays to the energy of the "knee" at 1015.5 eV. A nonresonant instability driven by the cosmic ray current is thought to be responsible for this effect. We perform two-dimensional, particle-in-cell simulations of this instability. We observe an initial growth of circularly polarized nonpropagating magnetic waves as predicted in linear theory. It is demonstrated that in some cases the magnetic energy density in the growing waves can grow to at least 10 times its initial value. We find no evidence of competing modes, nor of significant modification by thermal effects. At late times, we observe saturation of the instability in the simulation, but the mechanism responsible is an artifact of the periodic boundary conditions and has no counterpart in the supernova-shock scenario. © 2009. The American Astronomical Society. |
| first_indexed | 2024-03-07T00:54:47Z |
| format | Journal article |
| id | oxford-uuid:87abc0e3-f642-4eca-b541-625fbdc79d07 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:54:47Z |
| publishDate | 2009 |
| publisher | Institute of Physics Publishing |
| record_format | dspace |
| spelling | oxford-uuid:87abc0e3-f642-4eca-b541-625fbdc79d072022-03-26T22:12:05ZTWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKSJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:87abc0e3-f642-4eca-b541-625fbdc79d07EnglishSymplectic Elements at OxfordInstitute of Physics Publishing2009Ohira, YReville, BKirk, JTakahara, FIn supernova remnants, the nonlinear amplification of magnetic fields upstream of collisionless shocks is essential for the acceleration of cosmic rays to the energy of the "knee" at 1015.5 eV. A nonresonant instability driven by the cosmic ray current is thought to be responsible for this effect. We perform two-dimensional, particle-in-cell simulations of this instability. We observe an initial growth of circularly polarized nonpropagating magnetic waves as predicted in linear theory. It is demonstrated that in some cases the magnetic energy density in the growing waves can grow to at least 10 times its initial value. We find no evidence of competing modes, nor of significant modification by thermal effects. At late times, we observe saturation of the instability in the simulation, but the mechanism responsible is an artifact of the periodic boundary conditions and has no counterpart in the supernova-shock scenario. © 2009. The American Astronomical Society. |
| spellingShingle | Ohira, Y Reville, B Kirk, J Takahara, F TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKS |
| title | TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKS |
| title_full | TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKS |
| title_fullStr | TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKS |
| title_full_unstemmed | TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKS |
| title_short | TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF THE NONRESONANT, COSMIC-RAY-DRIVEN INSTABILITY IN SUPERNOVA REMNANT SHOCKS |
| title_sort | two dimensional particle in cell simulations of the nonresonant cosmic ray driven instability in supernova remnant shocks |
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