origin of high-energy cosmic rays vladimir ptuskin izmiran
TRANSCRIPT
Origin of high-energy cosmic rays
Vladimir Ptuskin
IZMIRAN
knee
Galactic extragalactic
GZK cutoff KpcEeVg
μG
Er = 1×
Z×B
JXE3
Sun
close binary
Galactic disk
pulsar
SNR
stellar wind
AGN
GRB
interacting galaxies
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
Fermi bubble
GC
WMAP haze
cosmic ray halo
cosmologicalshocks
RXJ1713.7-3945 H.E.S.S
Cosmic rays of Galactic origin:acceleration in supernova remnants and propagation in interstellar magnetic fields
M51
Jcr(E) = Qcr(E)×Te(E)
source confinement time of CR in the Galaxy;~ 108 yr at 1 GeV
~ 15% of SN kinetic energy transfer to cosmic rays,
basic diffusion model
2cm /s at 1 GeV,
228
e
a
HT D 3×10
2D
D p / Z , a = 0.3...0.6
H = 4 kpc, R = 20 kpc
sγ = 2.1...2.4 sourcespectrum
Ginzburg & Syrovatskii 1964, Berezinskii et al 1990,Strong & Moskalenko 1998 (GALPROP) , Strong et al 2007
“microscopic” theory: resonance scattering rg = 1/k, D ~
0.3vrgBtot2/Bres
2
-1snν = (30 yr)
Larmor radius wave number
sh shu R> 10
D(p)
, s-γs
σ + 2J ~ p γ = = 2
σ -1
shmax sh
uE 0.3 Ze B R
c
- 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 accelerationFermi 1949, Krymsky 1977, Bell 1978, …
Bohm limit
DB=vrg/3: Emax ≈ 1014 Z eV
SNR
ushshock
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 Bism = 5 10-6 G
2ism 10B/B ~
for testparticles !
numerical simulation of cosmic-ray acceleration in SNRPtuskin, 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. 2005 empirical; Bell 2004, Zirakashvili & VP 2008 theoretical)
- 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
15 1/6 -2/3knee sn,51 ej
•15 -1
knee sn,51 -5 w,6 ej
p c Z = 1.1×10 Ε n M eV,
p c Z = 8.4×10 Ε M u M eV
«knee» is formedat the beginningof Sedov stage
protons only
44 ( ) /sn sncp F p
calculated interstellar spectra produced by Type Ia, IIP, Ib/c, IIb SNRs(normalized at 103 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
<lnA> based on <Xmax>; data from Hoerandel 2007
0.54
pcD Ze
composition
solar modulation
more details:
spectra of p and He are differenthardening above 200 GeV/nucleon
concave source spectrum; acceleration at reverse shock; shock goes through Hewind of progenitor W-R star
different types of SN and different types of nuclei
Ptuskin et al. 2011
structure above the knee
Sveshnikova et al. 2011
single source modelof the knee
Erlykin & Wolfendale 1997Erlykin et al. 2011
Cosmic rays of extragalactic origin:acceleration in AGN jets andpropagation through backgroundradiation in the expanding Universe
Greisen 1966; Zatsepin & Kuzmin 1966energy scales are multiplied by1.2, 1.0, 0.75, 0.625 forAuger, 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 > 5.5 1019 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 > 1019.5 eV fast magnetars galaxy clusters 3 10-4 (Auger) 3 10-1 3 3 10- 4 10-3 10 kin. & 6 10-2 for X/gamma rotation strong shocks
8 10-3 for E>109 eV Lkin > 1044 erg/s
energy release in units 1040 erg/(s Mpc3)
FR II + RLQ
low-luminosity AGN
Koerding et al 2007
maximum energy of accelerated particlesLovelace 1976, Biermann & Strittmatter 1987, Blandford 1993, Norman et al 1995, Waxman 1995, Farrar & Gruzinov 2009, Lemoine & Waxman 2009, Ptitsyna & Troitsky 2010
22 3 2
jet
0.5 6
jetB
L c R L u R
E = Ze×β×B×lmax
2
1/2
1/2
max jet max
(4 )
86
cr cr
cr
cr
w u
B w
E Ze L E Ze Lc c
1/2
jet
η20 1/2 1/2 20 1/2cr2.7×10 Zβ L eV 1×10 Zβ L eVjet,45 jet,450.1
- Hillas criterion
- optimistic estimates of Emax for not ultrarelativistic jets
general electrodynamic estimate shock acceleration
- power of magnetized flow
proton-electron jet
Bell 2004
jet radiusjet velocity
Berezinsky & Grigoreva 1988,Allard et al 2005, Berezinsky et al. 2006
Galactic
Galactic
empirical dip model
empirical ankle transition model
VP, Rogovaya, Zirakashvili 2011
account for dmin(Ljet)
Auger data 30% of Fe
Allard 2009heavy 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 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.