Origin of high-energy cosmic rays Vladimir Ptuskin IZMIRAN

knee Galacticextragalactic GZK cutoff JXE3JXE3

N cr ~ cm -3 - total number density in the Galaxy w cr ~ 1.5 eV/cm 3 - energy density E max ~ 3x10 20 eV - max. detected energy r g ~ 1×E/(Z×3×10 15 eV) pc - Larmor radius at B=3 x G A 1 ~ – anisotropy at 1 – 100 TeV, slow diffusion Fermi bubble GC WMAP haze cosmic ray halo cosmological shocks

RXJ H.E.S.S Cosmic rays of Galactic origin: acceleration in supernova remnants and propagation in interstellar magnetic fields

M51 J cr (E) = Q cr (E)×T e (E) sourceconfinement time of CR in the Galaxy; ~ 10 8 yr at 1 GeV ~ 15% of SN kinetic energy transfer to cosmic rays, basic diffusion model H = 4 kpc, R = 20 kpc source spectrum Ginzburg & Syrovatskii 1964, Berezinskii et al 1990, Strong & Moskalenko 1998 (GALPROP), Strong et al 2007 “microscopic” theory: resonance scattering r g = 1/k, D ~ 0.3vr g B tot 2 /B res 2 Larmor radius wave number

- D(р) should be anomalously small both upstream and downstream; CR streaming creates turbulence in shock precursor Bell 1978; Lagage & Cesarsky 1983; McKenzie & Vőlk 1982 … diffusive shock acceleration Fermi 1949, Krymsky 1977, Bell 1978, … Bohm limit D B =vr g /3: E max ≈ Z eV SNR u sh shock compression ratio = 4 -condition of CR acceleration - Hillas criterion ! in young SNR from synchrotron X-rays obs. Koyama et al 1995 … & theory of CR streaming instability Bell & Lucek 2000, Bell 2004 … for B ism = G for test particles !

numerical simulation of cosmic-ray acceleration in SNR Ptuskin, Zirakashvili & Seo 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 B 2 /8π = ρu 2 /2 ( Voelk et al empirical; Bell 2004, Zirakashvili & VP 2008 theoretical) - account for Alfvenic drift w = u + V a 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 «knee» is formed at the beginning of Sedov stage protons only

calculated interstellar spectra produced by Type Ia, IIP, Ib/c, IIb SNRs (normalized at 10 3 GeV) 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 spectrum of all particles based on ; data from Hoerandel 2007 composition solar modulation

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

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

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 > eV (with Swift-BAT AGN density map) Abreu et al 2010

extragalactic sources needed in CR SN AGN jets GRB newly born accretion on at Е > eV fast magnetars galaxy clusters (Auger) kin. & for X/gamma rotation strong shocks for E>10 9 eV L kin > erg/s energy release in units erg/(s Mpc 3 ) FR II + RLQ low-luminosity AGN Koerding et al 2007

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 Hillas criterion - optimistic estimates of E max for not ultrarelativistic jets general electrodynamic estimateshock acceleration - power of magnetized flow proton-electron jet Bell 2004 jet radiusjet velocity

Berezinsky & Grigoreva 1988, Allard et al 2005, Berezinsky et al Galactic empirical dip model empirical ankle transition model VP, Rogovaya, Zirakashvili 2011 account for d min (L jet ) Auger data30% of Fe Allard 2009 heavy composition

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 5x10 18 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 to 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.