What do we know about the

identity of CR sources?

Boaz Katz, Kfir BlumEli Waxman

Weizmann Institute, ISRAEL

The cosmic-ray spectrum & Composition

Cosmic-ray E [GeV]

log [dJ/dE]

1 106 1010

E-2.7

E-3

Heavy Nuclei

Protons

Light Nuclei?

Galactic

X-Galactic)?(

[Blandford & Eichler, Phys. Rep. 87; Axford, ApJS 94; Nagano & Watson, Rev. Mod. Phys. 00]

Source: Supernovae)?(

Source?

Source?Lighter

Intra-cluster CRs

• Observed in radio, HXR• Will not be discussed here

• See D. Kushnir’s talk: [arXiv:0903.2271, 0903.2275, 0905.1950]

* Likely origin- Accretion shocks * Predictions for Fermi, TeV (HESS, MAGIC)

Galactic CR sources: Constraints

• Max >~1015eV

• Energy production rate LG,CR~(AdiskhCR)UCR/tCR

* UCR~1 eV/cm3,

* Propagation: 2nd-ary (& primary) composition

LG,CR~cAdiskUCR(disk/sec)~1049.5erg/100yr

25.0

secsec g/cmGeV10

/7.8,)/()(

Z

Zm

n

mnnij p

ii

p

ijji

[Blandford & Eichler, Phys. Rep. 87; Axford, ApJS 94]

Galactic CR sources: SNe?

• Motivation for SNe as sources: * LG,CR~10-1.5 LG,SN

* Max ~1015eV * e- acceleration to 1015eV from X emission

• TeV photons from SNRs (RXJ1713.7-3946,RXJ0852.0-4622)

* Claim: must be due to pp pion production Confirms CR ion production

[e.g. Koyama et al. 95]

[e.g. Aharonian et al. 04--07]

TeV must be due to e- IC

• pp origin in contradiction with radio, thermal-X

(non detection of thermal X n<~0.1/cm3):

• TeV consistent with e- IC, including “cutoffs”:

• Claims RE e- IC inconsistency: Detailed spectral shape near hc, where

theoretical predictions are highly uncertain

100

10

/

cm/1.05

1GHz

TeV

1

23.

L

Ln

L

L pe

Synch

pp

2

..

10BermTherm

pp

L

L

TeVcm/1.0

10,keVcm/1.0

11

3,

1

3.,

nh

nh cICcSynch

[Katz & Waxman 07]

SNR TeV lessons

• Search at high n SNRs: Strong Thermal X, weak non-Thermal

• Difficult to prove pp based on EM obs. Highly simplified, phenomenological models (and plenty of room for complications: inhomogeneous plasma, particle spectra…)

[Katz & Waxman 07]

3

1

2

GeV1cm/110

/3

n

L

L pe

IC

pp

PAMELA: New e+ sources?

• Apply

anti-p, e+ consistent with 2ndary origin

• Radiative e+ losses- depend on propagation in Galaxy (poorly understood)

* At 20GeV: frad~0.3~f10Be

* Above 20GeV: If PAMELA correct slightly rising frad()[Katz, Blum & Waxman 09]

)/()( sec Zm

n

mnnij p

ii

p

ijji

pp /

)/( eee

410

310

210

110

GeV10 GeV100

radf

What do we know about >1019eV CRs?

• Max : LB>1012 (2/) (/Z 1020eV)2 Lsun

(see Dermer’s talk)

• Composition

[Waxman 95, 04]

Composition clues

HiRes 2005

Westerhoff (Auger) 2009

What do we know about >1019eV CRs?

• Max : LB>1012 (2/) (/Z 1020eV)2 Lsun

• Composition: HiRes –protons, Auger- becoming heavier @

3x1019eV? !!Uncertain interaction cross sections

• Energy production rate: - LB>1012 Lsun & RL=/eB=40p,20kpc Likely X-

Galactic

[Waxman 1995; Bahcall & Waxman 03]

[Katz & Waxman 09]

• 2(dN/d)=2(dQ/d) teff. (teff. : p + CMB N +

Assume: p, dQ/d~(1+z)m-

• >1019.3eV: consistent with protons, 2(dQ/d) ~1043.7 erg/Mpc3 yr + GZK

• 2(dQ/d) ~Const.: Consistent with shock acceleration [Reviews: Blandford & Eichler 87; Waxman 06

cf. Lemoine & Revenu 06]

Flux & Spectrum

cteff [Mpc]GZK (CMB) suppression

log(2dQ/d) [erg/Mpc2 yr]

G-XG Transition at 1018eV?

Fine tuning Inconsistent spectrum

[Katz & Waxman 09]

What do we know about >1019eV CRs?

• Max : LB>1012 (2/) (/Z 1020eV)2 Lsun

• Composition HiRes –protons, Auger- becoming heavier Uncertain interaction cross sections

• Energy production rate - LB>1012 Lsun & RL=/eB=40p,20kpc Likely X-

Galactic - Consistent with protons, 2(dQ/d) ~1043.7 erg/Mpc3 yr + GZK

UHE CR sources• Constraints: - L>1012 (2/) Lsun

- 2(dQ/d) ~1043.7 erg/Mpc3 yr

- d(1020eV)<dGZK~100Mpc

!! No L>1012 Lsun at d<dGZK Transient Sources

• Gamma-ray Bursts (GRBs) ~ 102.5, L~ 1019LSun L/2 >1012 Lsun

(dn/dVdt)*E~10-9.5 /Mpc3 yr *1053.5erg ~1044 erg/Mpc3 yr Transient: T~10s << Tp~105 yr

• Active Galactic Nuclei (AGN, Steady): ~ 101 L>1014 LSun= few brightest

!! Non at d<dGZK Invoke:

* “Dark” (proton only) AGN * L~ 1014 LSun , t~1month flares

(from stellar disruptions)

[Blandford 76; Lovelace 76]

[Waxman 95, Vietri 95, Milgrom & Usov 95]

[Waxman 95]

[Boldt & Loewenstein 00]

[Farrar & Gruzinov 08]

Anisotropy

• Cross-correlation signal: Inconsistent with isotropy @ 98% CL (~1.5) Consistent with LSS

• If anisotropy signal real & no anisotropy at 60EeV/(Z~10)

primaries must be protons See M. Lemoine’s talk [arXiv:0907.1354]

Biased (source~gal for gal>gal )

[Kashti & Waxman 08]

The GRB “GZK sphere”

• LSS filaments: D~1Mpc, fV~0.1, n~10-6cm-3, T~0.1keV

B=(B2/8nT~0.01 (B~0.01G), B~10kpc

• Prediction:

p

D

B

few~)eV103( 20GRBsN[Waxman 95; Miralda-Escude &

Waxman 96, Waxman 04]

BBVGRBs

GRB

BBVp

DelaySpread

BBVp

fDN

R

fDd

c

d

fDd

2220

3

2

2

2052

2/1

20

2/10

10~)eV10(

yrGpc/5.0~

eV10/

Mpc100/yr10~~~

eV10/

Mpc100/3.0

Summary• Galactic <1015eV (<1019eV) - LG,CR~10-1.5 LG,SN & Max ~1015eV (1019eV)

suggest SNR (trans-rel. SN) sources - TeV from low n, non-thermal X SNR: e- IC - Search for pp in high n, strong thermal X SNR pp:IC[@1GeV]~3 (n/1cm3) * Anti-p, e+ data consistent with 2ndary origin Prediction: e+/(e++ e-)<0.2+-0.1 up to ~300GeV PAMELA slightly rising frad() [constrain CR prop. Models]

• X-Galactic >1019eV - Likely protons, 2(dQ/d) ~1043.7 erg/Mpc3 yr, LB>1012 Lsun

suggest: GRBs [AGN flares?] - Anisotropy constrains primary composition

• Difficult to uniquely identify sources via EM observations Search for HE ’s

Back up slides

X-ray filaments

• Claim: X-ray filaments require B>100G, much larger than required for IC explanation of TeV emission (B~10G).

• Claim based on the assumption: Filaments due to e- cooling (vs, e.g., B

variations). * No independent support to this assumption; * X-ray & RADIO filaments (Tycho, SN2006)

inconsistent with this assumption.

What is the e+ excess claim based on?

• On assumptions not supported by data/theory* primary e- & p produced with the same

spectrum, and e- and e+ suffer same frad

e+/e-~sec~-0.5

Or* detailed assumptions RE CR propagation, e.g. isotropic diffusion, D~, within an -independent box frad ~(-1)/2

• If PAMELA correct, these assumptions are wrong

(Correct) detailed CR propagation models must agree with simple, analytic results

derived from sec

• Example: Diffusion models with {D~K0 , box height L}

reproduce data for parameter combinations shown in fig. [Maurin et al. 01]

• Trivial explanation: [Katz, Blum & Waxman 09]

Require sec( =35GeV) to agree with the value inferred from B/Csec =[3.2,3.45,3.9] g/cm2

[green, blue, red]

The 1020eV challenge

RB eBRBR

R

BR

ccV p c

v

c

v

v/

1~

1 2

cec

BRL p

222

v/2

1v

84

v

v

sun122

20,

2

46

2

20

2

L10

erg/s10eV10/v

p

p

cL

2R

tRF=R/c)

l =R/

2 2

[Waxman 95, 04, Norman et al. 95]

Anisotropy clues: I

Galaxy density integrated to 75MpcCR intensity map (source~gal)

[Waxman, Fisher & Piran 1997]

• Auger collaboration: Correlation with low-luminosity AGN @ 99% AGN? • AGN trace LSS Correlation with large-scale structure? Unfortunately… Unclear.

GRB proton/electron acceleration

Electrons• MeV ’s:

• <1:

• e- () spectrum:

• e- ()energy production

erg/s1051L

5.210

2/ eee ddn

yrMpc

erg10erg10

yrGpc

10~

34452

32

e

ee d

nd

yrMpc

erg10erg10

yrGpc

5.03

445.533

[Waxman 95, 04] Afterglow, RGRB~SFR

Protons• Acceleration/expansion:

• Synchrotron losses:

• Proton spectrum:

• p energy production:

erg/s10/1025.22

20,5.50 pL

4/14/320,

2 ms10/10 tp

2/ ppp ddn

yrMpc

erg10

34422

e

ee

p

pp d

nd

d

nd

52

GRB Model Predictions

[Miralda-Escude & Waxman 96]