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粒子シミュレーションで観る粒子加速 : 衝撃波、リコネクション、降着円盤

粒子シミュレーションで観る粒子加速 : 衝撃波、リコネクション、降着円盤. 星野　真弘. Nonthermal Universe. Cosmic Rays. Solar Flares. ACRs. [Lin et al., 2003]. [Stone et al., 2008]. [Nagano & Watson, 2000]. Where and How are non-thermal particles produced? . Supernova Remnant Shock. Shock. Bamba et al. (2002). upstream.

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粒子シミュレーションで観る粒子加速 : 衝撃波、リコネクション、降着円盤

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  1. 粒子シミュレーションで観る粒子加速:衝撃波、リコネクション、降着円盤粒子シミュレーションで観る粒子加速:衝撃波、リコネクション、降着円盤 星野　真弘

  2. Nonthermal Universe Cosmic Rays Solar Flares ACRs [Lin et al., 2003] [Stone et al., 2008] [Nagano & Watson, 2000] Where and How are non-thermal particles produced?

  3. Supernova Remnant Shock Shock Bamba et al. (2002) upstream downstream SN1006 (Chandra) shock width＝ electron gyro-radius of 10 TeV Tycho’s SNR SN1006 Warren+ 2005 Bamba+ 2003

  4. Electron Energy Spectrum at SNR Shocks Fermi Acceleration Model SN1006, Chandra X-ray, Bamba et al. 2003; Long et al. 2003 V2= V1/4 V1 shock front upstream downstream

  5. Shock Numerical Experiment Particle-in-Cell (PIC) Simulation Modeling on Collisionless Shock Bｚ ｚ Eｙ particles wall ｙ p+,e- ｘ injection reflection 108-9particles fields

  6. Magnetic Bubbles in High Mach Number Shock Ma=137, wpe/wce=140, mi/me=100 Ion-Ion streaming Instability in Hot Electrons (Wu et al. 1984) large B field with B/B1 >15 & Va/Wci scale X/(V1/Wci) Shimada, MH & Amano,PoP 2010

  7. Magnetic Bubbles in High Mach Number Shock Ma=100, wpe/wce=71, mi/me=30 Ion-ion Weibel with Va/Wciscale Reconnection in 3D Katoand Takabe, 2010

  8. Magnetic Reconnection Solar & Stellar Flare, Magnetosphere, Accretion Disks, Pulsar Wind-Nebula, Astrophysical Jets,…. Plasma Heating & Nonthermal Particle Acceleration

  9. Reconnection around Heliopause Boundary Termination shock in Heliosphere Heliospheric Current Sheet Anomalous Cosmic Ray by Reconnection (Drake+ 2010)

  10. Gamma Ray Flares from Crab Nebula Pulsar Magnetosphere & Wind Crab Nebula Reconnection Model: CoronitiApJ 1990, Kirk+ PRL 2003, Zenitani & MH PRL 2005, Jaroschek & MH PRL 2009,... Tavani+, Science, 2011, Abdo+, Science, 2011

  11. Particle Trajectories, Magnetic Field Lines 2D PIC Simulation Particle Energies

  12. Stochastic particle acceleration in multiple magnetic islands during reconnection MH, PRL (2012)

  13. Fermi acceleration in magnetic islands 2ndorder Acceleration 1storder Acceleration MH, PRL (2012) Fermi, Phys. Rev. (1949)

  14. Plasma processes in Accretion Disk Courtesy of Kato Magneto-Rotational Instability (MRI) Velikov 1958, Chandrasekhar 1961, Balbus & Hawly 1991,…. Matsumoto & Tajima 1995,…Sano and Inutsuka 2001,….

  15. Magneto-Rotational Instability (MRI) MHD simulation B-lines weak magnetic field (β>>1)  β = 1-10 dynamo process Balbus and Hawley, 1998

  16. Collisionless Accretion Disk? Kinetic Magneto-Rotational Instability (MRI) and particle acceleration is important • Massive black hole (Sgr A*) • Radiatively Inefficient Accretion Flow (RIAF) • Accretion rate much smaller than the Bondi rate of 10-5M*/yr  net accretion rate 10-8M*/yr • thermal and nonthermal electrons (X-ray flare by observed Chandra & XMM-Newton), power law index p~1.3 < 2

  17. “Collisionless” MRI MHD + CGL + Landau Fluid Approx. Heat Flux q in Fourier space (Hammett+, PoP, 1992; Quataert+, ApJ, 2002; Sharma+, ApJ, 2006)

  18. MRI in anisotropic pressure MRI Mirror Mode z B W 0.8 1.2 r Im(w)/W Kepler Disk 0 0 1.1 45 q=tan-1(kr/kz) 1.0 90

  19. without Heat Flux Mirror Mode 2 7 1 Im(w)/W with Heat Flux 0 4 0 45 q=tan-1(kr/kz) 1 90 0.8 1.2 Im(w)/W 0 1.1 0 45 MRI q=tan-1(kr/kz) 1.0 90

  20. MRI and Reconnection in PIC simulation B β=100, Kepler rotationΩ 256x256x256 grids 40 particles/cell, periodic shearing box, electron-positron plasma green: magnetic field lines color contour: angular velocity

  21. Local rotating system with

  22. color contour: angular velocity green: B-lines

  23. E-2/3

  24. 2D-PIC simulation Z B R Kepler rotationΩ, Ω/ Ωc =0.1, β=1400, 300x300 grids 100 particles/cell, periodic box in meridian plane, electron-positron plasma

  25. 2D-PIC simulation Y B R Kepler rotationΩ, Ω/ Ωc =0.1, β=1400, 300x300 grids 100 particles/cell, periodic box in meridian plane, electron-positron plasma

  26. 2D-PIC simulation Z B R Kepler rotationΩ, Ω/ Ωc =0.1, gyro-radius Vi/Ωc =1.7x102 at t=0 β=20000, 200x200 grids 8000 particles/cell, periodic box in meridian plane, electron-positron plasma

  27. Onset of Reconnection After onset of Reconnection Before Reconnection Density T⊥> T// T⊥ ～ T// T⊥/T// Growth rate of tearing mode is enhanced for T⊥>T// Laval and Pellat (1968), Chen and Palmadesso (1984)

  28. thermal plasma is confined inside magnetic islands high energetic particles (γ>20) are located outside magnetic islands void E-4/3 middle energetic particles (γ>5) are located at outer edge of islands

  29. Summary Shocks Injection/Turbulent Reconnection/Kinetic MRI • High Mach number shocks with magnetic bubbles • Particle acceleration by multiple magnetic island reconnection in a large scale system • Onset of reconnection by T⊥> T// during MRI evolution • Hard energy spectrum with N(E)∝E-1 (in 2d & 3d PIC simulations) 公開粒子コード：Astro-pCANS http://www.astro.phys.s.chiba-u.ac.jp/pcans/

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