Origin%20of%20Ultra%20High%20Energy%20Cosmic%20Rays

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Origin of Ultra High Energy Cosmic Rays
Astrophysical Sources, Gamma-Ray Connection
Susumu Inoue (NAOJ)
astro-ph/0701835 (brief review)
GRBs
AGNs
clusters
collaborators
G. Sigl (APC), F. Miniati (ETH), E. Armengaud
(CEA)
F. Aharonian (MPIK), N. Sugiyama (Nagoya)
K. Asano (NAOJ)
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outline
1. general aspects
propagation extragalactic radiation and B fields
source candidates acceleration energetics
2. physics of selected UHECR source candidates
I. AGNs
different AGN types
II. GRBs
GeV-TeV g-rays
III. cluster accretion shocks
UHECR nuclei
UHE p-induced X/g-rays
UHECR-induced secondary X/g radiation signatures
neutrinos -gt Halzen
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The problem
UHECRs are the highest energy particles observed
in the universe, exceeding 1020 eV. Their origin
is unknown.
Emax 3x1020 eV 50J kinetic E of 100km/h
fastball (220km/h tennis serve)
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UHECR observations
before July (ICRC) 07
spectrum
at least up to 1020 eV
observations -gt Kampert
AGASA
HiRes
light dominant up to lt2x1019 eV?
composition
arrival directions
globally isotropic no ID with sources
Xmax g cm-2
gt1020 eV
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UHECRs energy losses during propagation
protons photopairphotopion
pgCMB? p ee- Epgt5x1017eVpgCMB? p p
Epgt7x1019eV
Fe
Lloss
p
(Greisen-Zatsepin-Kuzmin limit)
Lp, 20eV lt100 Mpc
g
nuclei photopairphotodisint.
AgCMB? A ee-AgFIRB? A-iN iN
Nagano Watson 00
e.g. Stecker Salamon 99
E
LFe, 20eV lt300 Mpc
nuclei possible at the highest E!
Watson astro-ph/0408110
Anchordoqui, Allard, Armengaud,
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extragalactic B fields
should be correlated with large scale struc.
very uncertain observationally and theoretically
crucial differences between theoretical models
Sigl, Miniati Ensslin 03,04
Dolag 04, 05 Brüggen 05
propagation -gt Das
Kang 07
also uncertain
Galactic B fields
secondary photon/neutrino signatures desirable to
pinpoint sources!
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top-down models very strongly constrained
topological defects, EHE n Z-bursts, UHECRons,
superheavy DM
Auger spectrum
Auger photon limits
Yamamoto arXiv 0707.2638
Semikoz arXiv 0706.2690
superheavy DM ruled out
spectral steepening at Egt1019.6 eV (6 sigma)
also claimed by HiRes
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UHECR sources acceleration
adapted from Yoshida Dai 98
Hillas plot
E ? Ze B R (v/c)
confinement
B
GRBs
B?R-1
acceleration vs
Emax
escape source lifetime adiab. expansion
loss radiative loss
AGN jets
clusters
R
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shock acceleration

• - power-law spectrum
• dN/dE?E-2 for strong shock
• very efficient
• up to 50 of kinetic energy

upstream
downstream
shock front

• consistent with observations
• in-situ earth-solar wind,
• SNRs, radio galaxy hot spots,

acceleration -gt Berezhko
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UHECR sources energy budget
kinetic E input into the universe
AGNs (radio galaxies)
z-dep. LF
Willott 01
Lkin-Lrad correlation
Rawlings 92
supernovae, GRBs
? star formation rate
Porciani Madau 01
ESN1051 erg
EGRB1053 erg, indep. of beaming
cluster accretion
Press Schechter mass function
Lacc(M)0.9x1046 (M/1015 MQ)5/3 erg/s
Keshet 04
UHECR budget
_at_1019 eV
differential (per unit z)
uCR 3x10-19 erg cm-3 1054 erg Mpc-3
dEkin/dz(dt/dz)?dL L dn/dL
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active galactic nuclei (AGNs)
GeV blazar
FR II radio galaxy
supermassive black hole accretion disk (flow)
high- power
radio-loud (relativistic jet)
lt1
low- power
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radio- quiet (no jet)
90
TeV blazar (BL Lac)
FR I radio galaxy
Seyfert galaxy
radio-quiet quasar
activity timescales 107-108 yr ltUHECR delay time
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AGNs acceleration sites
near-nucleus? R1013-1014 cm B104G?
Seyfert or radio-quiet quasar
EmaxEpglt1018eV
e.g. Szabo Protheroe 94
inconsistent with observed keV-MeV
UHECR accel. not expected
from Chandra webpage
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AGNs acceleration sites
near-nucleus?
low power (FR I) radio galaxy
UHECR accel. not expected
inner jet (blazar) R1016-1017 cm B0.1-1G
EmaxEpglt1020eV
e.g. Mannheim 93
adiabatic loss -gt n conversion escape?
shear-layer acceleration?
accel./escape non-trivial
from Chandra webpage
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AGNs acceleration sites
near-nucleus?
high power (FR II) radio galaxy
UHECR accel. not expected
inner jet (blazar)
EmaxEpglt1020eV
accel./escape non-trivial
hot spot R1021 cm B1mG
EmaxEesc1020-21eV
e.g. Rachen Biermann 93
from Chandra webpage
accel./escape easiest
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AGNs anisotropy expectations?
Takami 06
ns5x10-6 Mpc-3
anisotropy expectations for different AGN types
Takami, SI, in prep.
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AGNs UHECR-induced secondary emission
proton synchrotron from hot spots/knots
Aharonian 02
GZK radiation from intracluster AGNs
Armengaud, Sigl Miniati 05
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GRBs
internal external (forward reverse) shocks
UHECR accel. site
Waxman 95, Vietri 95
Gialis Pelletier 03 Wick, Dermer Atoyan 04
adapted from Meszaros 01
radio-IR-opt-X afterglow
prompt X-g emission
optical flash, radio flare
internal shocks
external reverse shock
external forward shock
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GRBs as UHECR sources
Waxman Miralda-Escude 96
time delayt(Ep,D)q2D/4c 107 yr Ep,20-2
D100Mpc2lMpcB-82
individual sources-gtnarrow spectrum at given time
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GRBs GeV-TeV g signature of UHECRs
Asano Inoue ApJ, in press arXiv0705.2910

• electronsprotons in internal shocks (prompt
  phase)
• pair cascading, pg interactions, various
  radiative processes
• parameters Esh, Dt, G, fBuB/ue, assume upue,
  pp2

proton synchrotron
inverse Compton
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GRBs GeV-TeV g signature of UHECRs
secondary pair synchrotron
muon synchrotron
double (multiple) breaks -gt proton signature
GLAST, MAGIC (II), HESS (II), VERITAS, CANG.III
MILAGRO, Auger
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cluster accretion shocks
Ryu 03
strong shocks
Mach no.
protons
Ep, max 1018-1019 eV
Kang, Rachen, Biermann 97
HOWEVER
Fe nuclei (Z26)
if Bs1 mG
EFe, maxgt1020 eV
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nuclei from cluster accretion shocks as UHECRs
Inoue, Sigl, Miniati Armengaud, PRL submitted
(astro-ph/0701167)
Emax
acceleration vs CMB losses, lifetime
shock radius, velocity, etc.
Hubble
Rs3.2 Mpc Vs2200 km/s
Bohm limit shock accel. time
tacc(20/3) rgc/Vs2
escape limit tescR2/5k(E) Emax/Z7x1018 eV
heavy nuclei Emax
for Bs1 mGEFe, max1020 eV
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UHECRs as nuclei from clusters
SI, Sigl, Miniati, Armengaud PRL,
submitted (astro-ph/0701167)
spectrum
anisotropy
with EGMF
fCR0.005-0.3
100 eventsgt4x1019eV
no EGMF
fCR0.002
composition
1000 eventsgt4x1019eV
consistent with current data (spectrum lt2
sigma) with some heavy enhancement
clear predictions for Auger, Telescope Array,
JEM-EUSO
1019 eV
1020 eV

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latest Auger results
composition
Unger arXiv 0706.1495
mixed composition at all E
becoming heavier at highest E?
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UHE proton-induced hard Xg emission from clusters
SI, Aharonian, Sugiyama 05
p(1019eV) gCMB? p ee- (1016eV)
ee-B(mG)?keV, ee-gCMB?TeV
Coma D100 Mpc
Suzaku? NeXT, Simbol-X, NuSTAR
HESS, MAGIC, CANG.3, VERITAS
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summary
AGNs
different likelihood for different types
high-power RG gt low-power RG gt radio-quiet

GRBs
tight energy budget
characteristic GeV-TeV signatures
cluster accretion shocks (nuclei)
consistent for some enhancement in heavy
composition
characteristic spectra, anisotropy, composition
hard X-rays TeV gamma-rays
other sources? starburst galaxies Galactic NS,
magnetars
none of these?
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concluding haiku
???? ????? ???? ????(?)
Matsushima, ah Matsushima, Matsushima. -
Matsuo Basho (?)