ELECTRON ACCELERATIONS AT HIGH MACH NUMBER SHOCKS: TWODIMENSIONAL PARTICLEINCELL SIMULATIONS IN VARIOUS PARAMETER REGIMES
Abstract
Electron accelerations at high Mach number collisionless shocks are investigated by means of twodimensional electromagnetic particleincell simulations with various Alfven Mach numbers, iontoelectron mass ratios, and the upstream electron {beta}{sub e} (the ratio of the thermal pressure to the magnetic pressure). We find electrons are effectively accelerated at a superhigh Mach number shock (M{sub A} {approx} 30) with a mass ratio of M/m = 100 and {beta}{sub e} = 0.5. The electron shock surfing acceleration is an effective mechanism for accelerating the particles toward the relativistic regime even in two dimensions with a large mass ratio. Buneman instability excited at the leading edge of the foot in the superhigh Mach number shock results in a coherent electrostatic potential structure. While multidimensionality allows the electrons to escape from the trapping region, they can interact with the strong electrostatic field several times. Simulation runs in various parameter regimes indicate that the electron shock surfing acceleration is an effective mechanism for producing relativistic particles in extremely high Mach number shocks in supernova remnants, provided that the upstream electron temperature is reasonably low.
 Authors:
 Department of Physics, Chiba University, Yayoicho 133, Inageku, Chiba 2638522 (Japan)
 Department of Earth and Planetary Science, University of Tokyo, Hongo 133, Bunkyoku, Tokyo 1130033 (Japan)
 Publication Date:
 OSTI Identifier:
 22039089
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Astrophysical Journal; Journal Volume: 755; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; ASTROPHYSICS; COMPUTERIZED SIMULATION; COSMIC ELECTRONS; COSMOLOGY; ELECTRON TEMPERATURE; INSTABILITY; IONS; MACH NUMBER; MASS; PLASMA; POTENTIALS; RELATIVISTIC RANGE; SHOCK WAVES; SUPERNOVA REMNANTS; TRAPPING
Citation Formats
Matsumoto, Yosuke, Amano, Takanobu, and Hoshino, Masahiro, Email: ymatumot@astro.s.chibau.ac.jp. ELECTRON ACCELERATIONS AT HIGH MACH NUMBER SHOCKS: TWODIMENSIONAL PARTICLEINCELL SIMULATIONS IN VARIOUS PARAMETER REGIMES. United States: N. p., 2012.
Web. doi:10.1088/0004637X/755/2/109.
Matsumoto, Yosuke, Amano, Takanobu, & Hoshino, Masahiro, Email: ymatumot@astro.s.chibau.ac.jp. ELECTRON ACCELERATIONS AT HIGH MACH NUMBER SHOCKS: TWODIMENSIONAL PARTICLEINCELL SIMULATIONS IN VARIOUS PARAMETER REGIMES. United States. doi:10.1088/0004637X/755/2/109.
Matsumoto, Yosuke, Amano, Takanobu, and Hoshino, Masahiro, Email: ymatumot@astro.s.chibau.ac.jp. Mon .
"ELECTRON ACCELERATIONS AT HIGH MACH NUMBER SHOCKS: TWODIMENSIONAL PARTICLEINCELL SIMULATIONS IN VARIOUS PARAMETER REGIMES". United States.
doi:10.1088/0004637X/755/2/109.
@article{osti_22039089,
title = {ELECTRON ACCELERATIONS AT HIGH MACH NUMBER SHOCKS: TWODIMENSIONAL PARTICLEINCELL SIMULATIONS IN VARIOUS PARAMETER REGIMES},
author = {Matsumoto, Yosuke and Amano, Takanobu and Hoshino, Masahiro, Email: ymatumot@astro.s.chibau.ac.jp},
abstractNote = {Electron accelerations at high Mach number collisionless shocks are investigated by means of twodimensional electromagnetic particleincell simulations with various Alfven Mach numbers, iontoelectron mass ratios, and the upstream electron {beta}{sub e} (the ratio of the thermal pressure to the magnetic pressure). We find electrons are effectively accelerated at a superhigh Mach number shock (M{sub A} {approx} 30) with a mass ratio of M/m = 100 and {beta}{sub e} = 0.5. The electron shock surfing acceleration is an effective mechanism for accelerating the particles toward the relativistic regime even in two dimensions with a large mass ratio. Buneman instability excited at the leading edge of the foot in the superhigh Mach number shock results in a coherent electrostatic potential structure. While multidimensionality allows the electrons to escape from the trapping region, they can interact with the strong electrostatic field several times. Simulation runs in various parameter regimes indicate that the electron shock surfing acceleration is an effective mechanism for producing relativistic particles in extremely high Mach number shocks in supernova remnants, provided that the upstream electron temperature is reasonably low.},
doi = {10.1088/0004637X/755/2/109},
journal = {Astrophysical Journal},
number = 2,
volume = 755,
place = {United States},
year = {Mon Aug 20 00:00:00 EDT 2012},
month = {Mon Aug 20 00:00:00 EDT 2012}
}

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