Page 1
Origin of Ultra High Energy Cosmic Rays
Susumu Inoue (NAOJ)
AGNs GRBs
clusters
astro-ph/0701835 (brief review)
collaborators:G. Sigl (APC), F. Miniati (ETH), E. Armengaud (CEA)F. Aharonian (MPIK), N. Sugiyama (Nagoya)
K. Asano (NAOJ)
Astrophysical Sources, Gamma-Ray Connection
Page 2
outline1. general aspects
2. physics of selected UHECR source candidates
III. cluster accretion shocks
I. AGNs
II. GRBs
UHECR nuclei
source candidates: acceleration & energetics
UHE p-induced X/-rays
GeV-TeV -rays
propagation: extragalactic radiation and B fields
neutrinos -> Halzen
different AGN types
UHECR-induced secondary X/ radiation signatures
Page 3
The problem:
UHECRs are the highest energy particlesobserved in the universe, exceeding 1020 eV.Their origin is unknown.
Emax~ 3x1020 eV ~50J ~kinetic E of 100km/h fastball (220km/h tennis serve)
Page 4
UHECR observationsspectrum at least up to 1020 eV
arrival directions
composition light dominantup to ~<2x1019 eV?
>1020 eV X max [g
cm
-2]
globally isotropicno ID with sources
AGASA
HiRes
before July (ICRC) 07observations -> Kampert
Page 5
UHECRs: energy losses during propagation
QuickTime˛ Ç∆ǻǵ êLí£ÉvÉçÉOÉâÉÄ
ǙDZÇÃÉsÉNÉ`ÉÉÇ å©ÇÈÇ…ÇÕïKóvÇ≈Ç∑ÅB
p+CMB→ p+ e+e- Ep>~5x1017eVp+CMB→ p+ Ep>~7x1019eV
Lp, 20eV <~100 Mpc
A+CMB→ A+ e+e-
A+FIRB→ A-iN +iNNagano & Watson 00
Fe
p
E
Lloss
LFe, 20eV <~300 Mpc
protons: photopair+photopion
nuclei: photopair+photodisint.
e.g. Stecker &Salamon 99
Watson astro-ph/0408110nuclei possible at the highest E!
Anchordoqui+, Allard+, Armengaud+, …
(Greisen-Zatsepin-Kuzmin limit)
Page 6
extragalactic B fields
Sigl, Miniati & Ensslin 03,04
should be correlated with large scale struc.
Dolag+ 04, 05Brüggen+ 05
crucial differences between theoretical models
very uncertain observationallyand theoretically
Galactic B fields also uncertain
Kang+ 07 propagation -> Das
secondary photon/neutrino signaturesdesirable to pinpoint sources!
Page 7
top-down models: very strongly constrainedtopological defects, EHE Z-bursts, UHECRons, superheavy DM…
Yamamoto+ arXiv: 0707.2638Auger spectrum
spectral steepening at E>1019.6 eV(6 sigma)
also claimed by HiRes
Auger photon limitsSemikoz+ arXiv: 0706.2690
superheavy DM ruled out
QuickTime˛ Ç∆TIFFÅià≥èkǻǵÅj êLí£ÉvÉçÉOÉâÉÄ
ǙDZÇÃÉsÉNÉ`ÉÉÇ å©ÇÈÇΩÇflÇ…ÇÕïKóvÇ≈Ç∑ÅB
Page 8
UHECR sources: acceleration
GRBs
AGN jets
clusters
adapted fromYoshida & Dai 98
R
B
B~∝R-1
“Hillas plot”E ≦ Ze B R (v/c)confinement
acceleration vs:Emaxescapesource lifetimeadiab. expansion lossradiative loss
Page 9
shock acceleration
- power-law spectrum dN/dE~∝E-2 for strong shock- very efficient up to ~50% of kinetic energy
shock frontupstream downstream
consistent with observations- in-situ: earth-solar wind, …- SNRs, radio galaxy hot spots, …
acceleration -> Berezhko
Page 10
UHECR sources: energy budget
differential (per unit z)dEkin/dz=(dt/dz)∫dL L dn/dL
UHECR budgetuCR ~3x10-19 erg cm-3
~1054 erg Mpc-3
kinetic E input into the universe
supernovae, GRBs
@1019 eV
AGNs (radio galaxies)z-dep. LF Willott+ 01Lkin-Lrad correlation Rawlings 92
∝ star formation rate Porciani &Madau 01
cluster accretion
Lacc(M)~0.9x1046 (M/1015 M)5/3 erg/sPress Schechter mass function
Keshet+ 04
EGRB=1053 erg, indep. of beamingESN=1051 erg
59
58
57
56
55
54
543210
z
radio galaxies supernovae gamma-ray bursts accretion
12
131415
Page 11
GeV blazaractive galactic nuclei (AGNs)supermassive black hole+accretion disk (flow)
radio-quiet(no jet)
radio-loud(relativistic jet)
FR IIradiogalaxy
FR Iradiogalaxy
TeV blazar(BL Lac)
Seyfert galaxy
low-power
high-power
radio-quiet quasar
activity timescales~107-108 yr~<UHECR delay time
QuickTime˛ Ç∆TIFFÅià≥èkǻǵÅj êLí£ÉvÉçÉOÉâÉÄ
ǙDZÇÃÉsÉNÉ`ÉÉÇ å©ÇÈÇΩÇflÇ…ÇÕïKóvÇ≈Ç∑ÅB
~90%~9%
~<1%
Page 12
AGNs: acceleration sites
from Chandra webpage
Seyfert or radio-quiet quasar near-nucleus?R~1013-1014 cm B~104G?Emax~Ep~<1018eV
e.g. Szabo & Protheroe 94
UHECR accel.not expected
inconsistent withobserved keV-MeV
Page 13
AGNs: acceleration sites
inner jet (blazar)R~1016-1017 cm B~0.1-1G
from Chandra webpage
Emax~Ep~<1020eVe.g. Mannheim 93
low power (FR I) radio galaxy near-nucleus?
adiabatic loss -> n conversion escape?
shear-layer acceleration?
accel./escape non-trivial
UHECR accel.not expected
Page 14
AGNs: acceleration sites
inner jet (blazar)
hot spot R~1021 cm B~1mG
from Chandra webpage
Emax~Ep~<1020eV
Emax~Eesc~1020-21eVe.g. Rachen & Biermann 93
high power (FR II) radio galaxy near-nucleus?UHECR accel.not expected
accel./escape non-trivial
accel./escape easiest
Page 15
AGNs: anisotropy expectations?
Takami+ 06
anisotropy expectationsfor different AGN types
Takami, SI+, in prep.
ns=5x10-6 Mpc-3
Page 16
AGNs: UHECR-induced secondary emission
Aharonian 02
Armengaud, Sigl & Miniati 05
proton synchrotron from hot spots/knots
“GZK” radiation from intracluster AGNs
Page 17
GRBs internal + external (forward + reverse) shocks
adapted from Meszaros 01
prompt X- emission
internal shocks
optical flash, radio flare
external reverse shock
radio-IR-opt-X afterglow
external forward shock
Waxman 95, Vietri 95UHECR accel. site
Gialis & Pelletier 03Wick, Dermer & Atoyan 04
Page 18
GRBs as UHECR sources Waxman & Miralda-Escude 96
time delayt(Ep,D)~2D/4c ~107 yr Ep,20
-2 D100Mpc2lMpcB-8
2
individual sources->narrow spectrum at given time
Page 19
GRBs: GeV-TeV signature of UHECRs Asano & InoueApJ, in pressarXiv:0705.2910
inverse Compton proton synchrotron
- electrons+protons in internal shocks (prompt phase)- pair cascading, p interactions, various radiative processes…- parameters: Esh, t, , fB=uB/ue, assume up=ue, pp=2
Page 20
GRBs: GeV-TeV signature of UHECRs
secondary pair synchrotron+ muon synchrotron+
double (multiple) breaks-> proton signature
GLAST, MAGIC (II), HESS (II), VERITAS, CANG.III …MILAGRO, Auger…
Page 21
cluster accretion shocks
accretion(minor merger)
Ryu+ 03
strong shocks
Kang, Rachen, Biermann 97
Fe nuclei (Z=26) EFe, max>~1020 eV
Ep, max~ 1018-1019 eVprotons
if Bs~1 GHOWEVER
Mach no.
Page 22
nuclei from cluster accretion shocks as UHECRs
heavy nuclei Emax
for Bs~1 GEFe, max~1020 eV
Inoue, Sigl, Miniati & Armengaud, PRL submitted (astro-ph/0701167)
Hubble
escape limittesc~R2/5(E)Emax/Z~7x1018 eV
acceleration vs CMB losses, lifetimeEmax
Rs~3.2 MpcVs~2200 km/s
tacc=(20/3) rgc/Vs2
shock radius, velocity, etc.
Bohm limit shock accel. time
Page 23
QuickTime˛ Ç∆TIFFÅià≥èkǻǵÅj êLí£ÉvÉçÉOÉâÉÄ
ǙDZÇÃÉsÉNÉ`ÉÉÇ å©ÇÈÇΩÇflÇ…ÇÕïKóvÇ≈Ç∑ÅB
QuickTime˛ Ç∆TIFFÅià≥èkǻǵÅj êLí£ÉvÉçÉOÉâÉÄ
ǙDZÇÃÉsÉNÉ`ÉÉÇ å©ÇÈÇΩÇflÇ…ÇÕïKóvÇ≈Ç∑ÅB
UHECRs as nuclei from clusters
with EGMF
no EGMF
spectrum
composition
anisotropy
1019 eV 1020 eV
fCR~0.005-0.3
fCR~0.002
SI, Sigl, Miniati, ArmengaudPRL, submitted(astro-ph/0701167)
consistent with current data(spectrum <2 sigma)with some heavy enhancement
clear predictions forAuger, Telescope Array, JEM-EUSO…
100 events>4x1019eV
1000 events>4x1019eV
Page 24
latest Auger results QuickTime˛ Ç∆TIFF (LZW) êLí£ÉvÉçÉOÉâÉÄǙDZÇÃÉsÉNÉ`ÉÉÇ å©ÇÈÇΩÇflÇ…ÇÕïKóvÇ≈Ç∑ÅB
composition Unger+ arXiv: 0706.1495
mixed compositionat all E
becoming heavierat highest E?
Page 25
UHE proton-induced hard X+ emission from clusters
Suzaku?NeXT, Simbol-X, NuSTAR
HESS, MAGIC,CANG.3, VERITAS…
SI, Aharonian, Sugiyama 05
ComaD=100 Mpc
p(1019eV) +CMB→ p+ e+e- (1016eV)
e+e-+B(~G)→keV, e+e-+CMB→TeV
Page 26
summary
cluster accretion shocks (nuclei)
characteristic spectra, anisotropy, composition hard X-rays + TeV gamma-rays
AGNs
GRBstight energy budget
characteristic GeV-TeV signatures
consistent for some enhancement in heavy composition
other sources?starburst galaxies …Galactic NS, magnetars …
none of these?
different likelihood for different types high-power RG > low-power RG > radio-quiet
Page 27
concluding haiku
「松島や ああ松島や 松島や」 松尾芭蕉(?)
“Matsushima, ah Matsushima, Matsushima.” - Matsuo Basho (?)
宇宙線 ああガンマ線 ニュートリノ
“Cosmic rays, ah Gamma-rays, Neutrinos.”
The real beauty will be in the combination of the techniques!