ガンマ線観測からハドロン加速は井上 進 （京大理）どこまで押さえられたかoutline
0. introduction
1. Galactic CRs: SNRs
2. UHECRs: AGNs (blazars)
GRB protons(GRB nuclei)(cluster nuclei)
3. knee-ankle CRs: clusters
as hadron indicators
gamma-rays:vsneutrinos:
easy to detect
not easy to detect
easily contaminated
not easily contaminatedeasily absorbed
not easily absorbed

observed CR spectrum
up to knee (<1015-16 eV)
Galactic SNRs?
likely, but not yet definitiveknee-ankle (1015-16-1018 eV)
Galactic? no new source?

kneeankleGaisser 05

toeabove ankle (>1018 eV)extragalactic: AGNs?
GRBs?
???

Galactic CRs: SNRs
Cas A VLAenergetics

LGCR~1041 erg/s~0.1xESN/tSN

radio/X evidence for electron acceleration
BUT
Lagage & Cesarsky 83
simple theory: Emax~v/c Z e B (vT)
<1014eV Z v5000km/s2T1000yrB3mG <Eknee
no definitive evidence yet for proton acceleration

SNRs: X-rays in high resolution
Chandrashock surfaces ~ very thin filaments→ B~ few 100 mG
CR B amplification?
Lucek Bell 00, Bell 04acceleration up to Eknee!

Bamba+ 03

SNRs: X-ray variability!

Uchiyama+ 07, Nat 449, 576
shock surface hot spots~ yr time scale variability→ B~1mG!

RX J1713.7-3946 Chandrafavors p-p p0 as TeV

SNRs: TeV gamma-ray imaging Aharonian+ 04 Nat., 05, 06
RX J1713.7-3946(discovered by CANGAROO Enomoto+ 02)

p-p pi0e-ICp-p p0 likely (+some e-IC)?

Emax~100 TeV< Eknee
later/other SNRs up to Eknee?

HESS

SNRs: Fermi results

Abdo+ 10 (Funk, Uchiyama)

Cas A

clear detection
clear shell morphology
BUT unclear on p0 bump…
-> <100 MeV observations
n observations!

RX J1713.7-3946

SNRs: Fermi results

young vs middle-aged SNRs

middle-aged SNRs:
1-10 GeV spectral break -> early CR escape?
evidence of interaction with molecular clouds

宇宙線が逃げていく
様子が見えてきたother Galactic CR source candidates
hints from TeV
stellar winds Aharonian+ 07
p-p pi0 or e-IC?
pulsar wind nebulae?
g-ray binaries Aharonian+ 05 Sci., 06(microquasars) Albert+ 06 Sci.
BH (microblazar) or NS (wind nebulae)?
n source?

Galactic GRBse.g. Wick, Dermer & Atoyan 04

LS5039TeV unID sources: dark accelerators!
SuzakuHESSpossibilities- stellar winds- offset pulsar nebulae- old SNRs
- GRB remnants- photoexcitation of CR nuclei- dark matter???
陽子起源、 >~100 TeVまで加速
明確なカットオフの兆候なし-> knee宇宙線源？

HESS J1616-508
Matsumoto+ 06

Cherenkov Telescope Array: future of GeV-TeV astronomy

CTA

いろいろな宇宙物理の他、ダークマター探査、ローレンツ不変性破れの検証など

PeVatron search: wide field facilities

gg opacity for Galactic interstellar radiation field
20,0,90
0,0,020,0,180

R, z(kpc), (deg)Moskalenko+ 06

additional absorption for < few 100 TeV possible

UHECR sources: acceleration
adapted from

“Hillas plot” Yoshida & Dai 98

E ≦ Ze B R (v/c)
confinement

magnetars

Emax acceleration vs:
B

GRBs
B~∝R-1

escapesource lifetime
adiab. expansion loss
radiative loss

AGN jetsclustersR

heavy favorite: AGNs
leading contender: GRBs
dark horse: clusters, etc.

UHECR sources: energy budget
kinetic E input into the universe

SI, arXiv:0809.3205
AGNs (radio galaxies)
Willott+ 01
z-dep. LFLkin-Lrad correlation Rawlings 92

supernovae, GRBs
∝ star formation rate
Porciani & Madau 01, Le & Dermer 07

EGRB=1054 erg, indep. of beaming

cluster accretion
Press Schechter mass function
Lacc(M)~0.9x1046 (M/1015 MQ)5/3 erg/s
Keshet+ 04

differential (per unit z)
dEkin/dz=(dt/dz)∫dL L dn/dL

UHECR budget @1019 eV
uCR ~3x10-19 erg cm-3~1054 erg Mpc-3

local extragalactic gamma-ray horizon
emission fromsecondary pairs(pair halos)?

gg(>400 TeV)<20kpc
Coppi & Aharonian 97FR 2
radiogalaxy

active galactic nuclei (AGNs)
supermassive black hole+accretion disk (flow)
radio-loud(relativistic jet)radioquiet(no jet)~90%

Seyfert galaxy
radio-quiet quasar

GeV blazar

highpower~<1%

low~9%power
FR 1
radiogalaxy

TeV blazar(BL Lac)strong nonthermalemission=particle acceleration

activity timescales~106-108 yr

AGNs: acceleration sites
high power (FR 2) radio galaxy

near-nucleus
highest E not expected
inner jet (blazar)
Emax~Epg~<1020eV
accel./escape nontrivial
hot spot
R~1021 cm B~1mG

Emax~Eesc~1020-21eV

accel./escape easier
bow shock
R~1023 cm B~0.1mG

Emax~Eesc~1020eVBerezhko 08
from Chandra webpage

accel. nontrivial

Cen A
Cen A excess events:
UHECR (nuclei)
accelerated in jet core-> escape along jet-> deflected by lobe MF+deflected by Galactic MF
c.f. Rachen 08
Lemoine & Waxman 09

Moskalenko+ 09

proton blazar modele-+B→e-+gLE
p+gLE→N+ p0, p+-Mannheim 93, etc

p0→2g p+-→e+-+3ng+gLE → e+e-

proton-induced cascade

e+e-+B→ e+e-+gp+B→p+g

proton synchrotron

Böttcher+ 09

difficulties
1. poor fit to broadband spectra?

2. tpg too long(?) to explain<day timescale X-TeV correlations
subminute TeV variability

however:
can we still see UHE proton signatures
mixed with leptonic emission?

leptonic+hadronic emission model
Cerruti, Zech, SI & Boisson, in prep.
leptonic model of Katarzynski, Sol & Kus 01- one zone synchrotron+SSC- electron spectrum: phenomenological broken power-law- internal gg pair absorption
hadronic processes- proton synchrotron- photomeson interactions (SOPHIA)- syn+IC emission secondary pairs(- Bethe-Heitler pair production)(- muon synchrotron)
EBL: Kneiske+04 best fit modelcompare with PKS 2155-304 2008 simultaneous data
HESS, Fermi, RXTE, ATOM Aharonian+ 09

leptonic emission model

d=32, B=0.018 G, R=4.7x1016 cm2

leptonic+hadronic emission modelp syne+- syn

d=25, B=0.25 G, R=5.2x1015 cm2, Up/Ue=1
GeV “feature”~ p sync? test with variabilityhadronic emission model

d=20, B=70G, R=1.0x1015 cm2, Up/Ue=104
TeV “excess”~ pg cascade? test with variability

short timescale flare from jet-star interaction?
Aharonian+ 06
HESS observations ofmin timescale flarein PKS 2155-304

p-p and/or p sync. gfrom jet-starinteractions?
Barkov, Aharonian+arXiv:1012.1787

hot spots: UHECR-induced emission
pg pair cascade
Mannheim+ 91

proton synchrotron
Aharonian 02

generally not strong,
but worth reconsideration
for CTAGRBs: acceleration sites
Waxman 95
Vietri 95

adapted from Meszaros 01

prompt X-g emissioninternal shocks
R~G2ctvar~1012-1016 cm
B~106-103 G
Grel~1

optical flash, radio flareradio-IR-opt-X afterglow

external reverse shock external forward shock
R~Rdec~1016 cm
B~10 G
Grel~1R~Rdec-RNR~1016-1018 cm
B~10-0.01 G? >>BISM
Grel>>1

GRBs as UHECR sources: diagnostics
time delayt(Ep,D)~q2D/4c~107 yr Ep,20-2 D100Mpc2lMpcB-82

CR spectra of individual sources
narrow at given time?
-> need large statistics

secondary neutral (gamma & neutrino)
signatures essential to identify sources

Waxman &Miralda-Escude 96

BpB

Bγe+
νμ γ
νeγγe-νμμγ© K. Asanoγπn+γγγγ+eeγ
γ
μ：106MeV, tdec＝2.2×10-6 s

GRB GeV-TeV emission from electrons+protons- electrons+protons acceleration in internal shocks (prompt phase)- pair cascading, pg interactions, various radiative processes…
- parameters: pulse energy Esh, pulse timescale Dt, G, fB=uB/ue
fix Epk=300 keV, b=2.5, assume up=ue, pp=2
Asano & SI 07- fluence spectra, z=0.1, no intergalactic gg
p/e =1 (proton-electron equip.) Eg,iso =1053 erg
proton synchrotroninverse Compton
B/e=0.1B/e=30

GRB GeV-TeV emission

Asano & SI 07

p/e =1 (proton-electron equip.) Eg,iso =1053 erg
secondary pair synchrotron+muon synchrotron+

B/e=1

double (multiple) breaks-> proton signature
Fermi, Cerenkov telescopes…

B/e=30

GRB GeV-TeV

tgg~ngRsgg<1=B/e

proton-induced g components require B/e>1

GRB GeV-TeV - UHECR - neutrino connection

UHECR escapetexp < tpg~ngRspg
n conversion

texp > tpg

neutrino emission

tgg~ngRsgg<1=B/e

proton-induced g components: B/e>1
GUHE>~300 (Dt/0.1s)-0.3(E/1051erg)0.5
GeV-TeV (inc. IC) : tgg<1 -> texp < tpg efficient UHECR escapeGRBs: Fermi results
prompt- prompt GeV
in bright GRBs
- MeV extension
at least to
10-30 GeV
- excess hard
compt. forbrightest GRBs

Gehrels+ 09- bothlong (few 100s),short (few s)

GRBs: Fermi results- GeV afterglow
up to few ks∝ t-1.2-t-1.5

afterglow (1 hr)

Gehrels+ 09- consistent withmost GRBs
having GeV
prompt+afterg.
- BUTphysics unclear
due to low GeV
photon statistics

hadronic emission model:
GRB 090510
Asano+ 09

R=1014 cm
G=1500UB/Ug=0.001
Lp/Lg=200

fn=Ln/Lg=0.40

hadronic emission model:
GRB 090902B
Asano, SI & Meszaros 10

f() [erg/cm2/s]

R=1014 cm, G=1300, Up/Ug=3, UB/Ug=110-5

R=1014 cm
G=1300UB/Ug=1
Lp/Lg=3
10-6Total

fn=Ln/Lg=0.042- +courtesy Asano
hadronic process timescales
14-3t [s]R=10cm,
G=1500,L/L=10, Lp/Lg=200
B g510104103102110100
10-1
10-2

tIC
The cooling timescales(comoving frame) ofprotons due tosynchrotron, inverse
Compton, Bethe-Heitler,
and photopion
production are plotted.
The dynamicaltimescale is R/Gc.

tBH
tp
tsyn

tdyn
A long coolingtimescale -> lowefficiency ofpion-production

tacc The maximum
energy is determinedby the dynamicaltimescale.

light curve modelingcourtesy Asanocurrently leptonic only

1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1

Lightcurve

100keV
100 MeVGeV

100 GeVCTAによるGRB観測

1. 10 GeVに迫るエネルギー閾値 (<<現行IACT)-> 宇宙背景放射光 (EBL) によるgg吸収を受けにくい
2. 高速指向性能：180deg/20sec for LST (MAGIC2と同等)-> long GRBの即時放射中に観測開始
3. 莫大な有効面積：>104m2@30GeV (Fermiの1万倍)-> 圧倒的な光子統計、詳細なスペクトル・時間変動の情
Fermi LAT GRB 080916C
>100
MeV

> 10 GeV photon
Fermi数発 ->>1GeV
CTA 数万発！

Abdo+ 09

Galactic CRs: knee-ankle region

KASKADE

SNRs in stellar winds? multiple SNRs in OB associations
Galactic wind termination shocks?
cluster merger/accretion shocks?
low-energy extension of UHECR spectra (no new source)?

knee-ankle CRs from clusters and p-p neutrinos
pCR+pICM→ p0, p+-

p+- →2nm, neBerezinsky+ 97
Colafrancesco & Blasi 98

Murase, SI, Nagataki 08- promising for IceCube- probe of PeV
CR confinement(difficult with gdue to gg horizon)
IceCube-40 limit Abbasi+ arXiv:1012.2137

まとめ
系内宇宙線源SNR（長年最有力）
X線観測 -> 磁場増幅
GeV-TeV -> ハドロンっぽいが未確定

ニュートリノで決定打
宇宙線逃げる様子が見え

超高エネルギー宇宙線源

系外以外はまだまだ不明
blazar GeV-TeV: 一部／全部ハドロン解釈もまだあり？
GRB GeV: ハドロン解釈も充分可能-> 今後時間変動から識別
ニュートリノで決定打
knee-ankle宇宙線

ニュートリノのみ？

宇宙線 ああガンマ線ニュートリノ
TAや ああCTA IceCube （Tibet等も）