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Origin of high-energy cosmic rays Vladimir Ptuskin IZMIRAN

Origin of high-energy cosmic rays Vladimir Ptuskin IZMIRAN. J X E 3. knee. Galactic. extragalactic. GZK cutoff. cosmological shocks. Fermi bubble. cosmic ray halo. WMAP haze. GC. N cr ~ 10 -10 cm -3 - total number density in the Galaxy w cr ~ 1.5 eV/cm 3 - energy density

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Origin of high-energy cosmic rays Vladimir Ptuskin IZMIRAN

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  1. Origin of high-energy cosmic rays Vladimir Ptuskin IZMIRAN

  2. JXE3 knee Galactic extragalactic GZK cutoff

  3. cosmological shocks Fermi bubble cosmic ray halo WMAP haze GC Ncr~ 10-10 cm-3- total number density in the Galaxy wcr ~ 1.5 eV/cm3- energy density Emax ~ 3x1020 eV - max. detected energy rg ~ 1×E/(Z×3×1015 eV) pc - Larmor radius at B=3x10-6 G A1 ~ 10-3 – anisotropy at 1 – 100 TeV, slow diffusion

  4. RXJ1713.7-3945 H.E.S.S Cosmic rays of Galactic origin: acceleration in supernova remnants and propagation in interstellar magnetic fields

  5. basic diffusion model Ginzburg & Syrovatskii 1964, Berezinskii et al 1990, Strong & Moskalenko 1998 (GALPROP) , Strong et al 2007 Jcr(E)= Qcr(E)×Te(E) H = 4 kpc, R = 20 kpc source confinement time of CR in the Galaxy; ~ 108 yr at 1 GeV M51 ~ 15%of SN kinetic energy transfer to cosmic rays, source spectrum “microscopic” theory: resonance scattering rg = 1/k, D ~ 0.3vrgBtot2/Bres2 Larmor radius wave number

  6. diffusive shock acceleration ush Fermi 1949, Krymsky 1977, Bell 1978, … shock SNR for test particles ! compression ratio = 4 • condition of CR • acceleration - D(р) should be anomalously small bothupstreamand downstream;CR streaming creates turbulence in shock precursor Bell 1978; Lagage & Cesarsky 1983; McKenzie & Vőlk 1982 … Bohm limit DB=vrg/3: - Hillas criterion ! Emax≈ 1014Z eV for Bism = 5 10-6 G in young SNRfrom synchrotron X-rays obs.Koyama et al 1995 … & theory of CR streaming instabilityBell & Lucek 2000, Bell 2004 …

  7. numerical simulation of cosmic-ray acceleration in SNR Ptuskin, Zirakashvili & Seo 2010 • spherically symmetric hydrodynamic eqs. • including CR pressure + diffusion-convection • eq. for cosmic ray distribution function • (compare to Berezhko et al. 1996, • Berezhko & Voelk 2000; Kang & Jones 2006) • Bohm diffusion in amplified magnetic field • B2/8π = 0.035 ρu2/2 • ( Voelk et al. 2005empirical; Bell 2004, • Zirakashvili & VP 2008theoretical) • account for Alfvenic drift w = u + Va • upstream and downstream • - relative SNR rates: SN Ia : IIP : Ib/c : IIb • = 0.32 : 0.44 : 0.22 : 0.02 • Chevalier 2004, Leaman 2008,Smart et al 2009 protons only «knee» is formed at the beginning of Sedov stage

  8. calculated interstellar spectra produced by Type Ia, IIP, Ib/c, IIb SNRs (normalized at 103 GeV) solar modulation spectrum of all particles data from HEAO 3, AMS, BESS TeV, ATIC 2, TRACER experiments data from ATIC 1/2, Sokol, JACEE, Tibet, HEGRA, Tunka, KASCADE, HiRes and Auger experiments composition <lnA> based on <Xmax>; data from Hoerandel 2007

  9. more details: hardening above 200 GeV/nucleon spectra of p and He are different structure above the knee Ptuskin et al. 2011 Sveshnikova et al. 2011 different types of SN and different types of nuclei single source model of the knee concave source spectrum; acceleration at reverse shock; shock goes through He wind of progenitor W-R star Erlykin & Wolfendale 1997 Erlykin et al. 2011

  10. Cosmic rays of extragalactic origin: acceleration in AGN jets and propagation through background radiationin the expanding Universe energy scales are multiplied by 1.2, 1.0, 0.75, 0.625 for Auger, HiRes, AGASA, & Yakutsk Greisen 1966; Zatsepin & Kuzmin 1966 Aloisio et al 2007

  11. Auger – heavy composition; anisotropy (69 events at >57 EeV) Abreu et al 2010, Matthiae 2010, PAO 2010 HiRes – proton composition; no significant anisotropy (13 events) Abbasi et al 2009,Sokolsky et al 2010 first results of Telescope Array (13 events) support HiRes Pierre Auger Observatory, 69 events at E > 5.5 1019 eV (with Swift-BAT AGN density map) Abreu et al 2010

  12. extragalactic sources energy release in units1040erg/(sMpc3) needed in CR SN AGN jets GRB newly born accretion on atЕ > 1019.5eV fast magnetars galaxy clusters 3 10-4(Auger)3 10-13 3 10-4 10-310 kin.& 6 10-2forX/gamma rotationstrong shocks 8 10-3for E>109eV Lkin> 1044 erg/s low-luminosity AGN FR II + RLQ Koerding et al 2007

  13. maximum energy of accelerated particles Lovelace 1976, Biermann & Strittmatter 1987, Blandford 1993, Norman et al 1995, Waxman 1995, Farrar & Gruzinov 2009, Lemoine & Waxman 2009, Ptitsyna & Troitsky 2010 - Hillas criterion general electrodynamic estimate shock acceleration - power of magnetized flow proton-electron jet jet velocity jet radius Bell 2004 - optimistic estimates of Emax for not ultrarelativistic jets

  14. Berezinsky & Grigoreva 1988, Allard et al 2005, Berezinsky et al. 2006 VP, Rogovaya, Zirakashvili 2011 account for dmin(Ljet) empirical dip model Galactic heavy composition empirical ankle transition model Allard 2009 Auger data 30% of Fe Galactic

  15. Conclusions Cosmic ray origin scenario where supernova remnants serve as principle accelerators of cosmic rays in the Galaxy is strongly confirmed by recent numerical simulations. SNRs can provide cosmic ray acceleration up to 5x1018 eV. High-accuracy measurements reveal deviations of cosmic ray spectra from plain power laws both below and above the knee that requires theory refinement. More data on spectrum, composition, and anisotropy are needed in the energy range 1017 to 1019 eV, where transition from Galactic to extragalactic component occurs. Understanding discrepancy between Auger and HiRes results on composition and anisotropy is necessary for understanding of cosmic ray origin at the highest energies.

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