RELATIVISTIC ELECTRON SHOCK DRIFT ACCELERATION IN LOW MACH NUMBER GALAXY CLUSTER SHOCKS

• Matsukiyo, Shuichi

  Department of Earth System Science and Technology, Kyushu University

• Ohira, Yutaka

  High Energy Acceleration Research Organization

• Yamazaki, Ryo

  Department of Physics and Mathematics, Aoyama Gakuin University

• Umeda, Takayuki

  Solar-Terrestrial Environment Laboratory, Nagoya University

Abstract

An extreme case of electron shock drift acceleration (SDA) in lowMach number collisionless shocks is investigated as a plausible mechanism for the initial acceleration of relativistic electrons in large-scale shocks in galaxy clusters, where the upstream plasma temperature is of the order of 10 keV and the degree of magnetization is not too small. One-dimensional electromagnetic full particle simulations reveal that, even when a shock is rather moderate, a part of the thermal incoming electrons are accelerated and reflected through relativistic SDA and form a local non-thermal population just upstream of the shock. The accelerated electrons can self-generate local coherent waves and further be back-scattered toward the shock by those waves. This may be a scenario for the first stage of the electron shock acceleration occurring at the large-scale shocks in galaxy clusters, such as CIZA J2242.8+5301, which have well-defined radio relics.

Journal

• Astrophysical Journal

  Astrophysical Journal 742 47-1-47-9, 2011-11-03

  The American Astronomical Society

Keywords

• acceleration of particles
• galaxies
• clusters
• general
• plasmas
• radio continuum
• relativistic processes
• shock waves

Details

• CRID: 1050861482658363776
• NII Article ID: 120003483454
• NII Book ID: AA00553242
• HANDLE: 2324/20259
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles