What do we know about the identity of CR sources? Boaz Katz, Kfir Blum Eli Waxman Weizmann Institute, ISRAEL

The cosmic-ray spectrum & Composition Cosmic-ray E [GeV] log [dJ/dE] 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? Lighter

Intra-cluster CRs Observed in radio, HXR Will not be discussed here See D. Kushnir ’ s talk: [arXiv: , , ] * Likely origin- Accretion shocks * Predictions for Fermi, TeV (HESS, MAGIC)

Galactic CR sources: Constraints Max  >~10 15 eV Energy production rate L G,CR ~(A disk h CR )U CR /t CR * U CR ~1 eV/cm 3, * Propagation: 2 nd -ary (& primary) composition  L G,CR ~cA disk U CR (  disk /  sec )~ erg/100yr [Blandford & Eichler, Phys. Rep. 87; Axford, ApJS 94]

Galactic CR sources: SNe? Motivation for SNe as sources: * L G,CR ~ L G,SN * Max  ~10 15 eV * e - acceleration to eV from X emission TeV photons from SNRs (RXJ ,RXJ ) * Claim: must be due to pp pion production  Confirms CR ion production [e.g. Koyama et al. 95] [e.g. Aharonian et al ]

TeV must be due to e - IC pp   origin in contradiction with radio, thermal-X (non detection of thermal X  n<~0.1/cm 3 ): TeV consistent with e - IC, including “ cutoffs ” : Claims RE e - IC inconsistency: Detailed spectral shape near h c, where theoretical predictions are highly uncertain [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]

PAMELA: New e+ sources? Apply  anti-p, e + consistent with 2 nd ary origin Radiative e + losses- depend on propagation in Galaxy (poorly understood) * At 20GeV: f rad ~0.3~f 10 Be * Above 20GeV: If PAMELA correct  slightly rising f rad (  ) [Katz, Blum & Waxman 09]

What do we know about >10 19 eV CRs? Max  : L B >10 12 (  2 /  ) (  /Z eV) 2 L sun (see Dermer ’ s talk) Composition [Waxman 95, 04]

Composition clues HiRes 2005

Westerhoff (Auger) 2009

What do we know about >10 19 eV CRs? Max  : L B >10 12 (  2 /  ) (  /Z eV) 2 L sun Composition: HiRes – protons, Auger- becoming 3x10 19 eV? !!Uncertain interaction cross sections Energy production rate: - L B >10 12 L sun & R L =  /eB=40  p,20 kpc  Likely X-Galactic

[Waxman 1995; Bahcall & Waxman 03] [Katz & Waxman 09]  2 (dN/d  )=  2 (dQ/d  ) t eff. (t eff. : p +  CMB  N +  Assume: p, dQ/d  ~(1+z) m  -  > eV: consistent with protons,  2 (dQ/d  ) ~ erg/Mpc 3 yr + GZK  2 (dQ/d  ) ~Const.: Consistent with shock acceleration [Reviews: Blandford & Eichler 87; Waxman 06 cf. Lemoine & Revenu 06] Flux & Spectrum ct eff [Mpc] GZK (CMB) suppression log(  2 dQ/d  ) [erg/Mpc 2 yr]

G-XG Transition at eV? Fine tuning Inconsistent spectrum [Katz & Waxman 09]

What do we know about >10 19 eV CRs? Max  : L B >10 12 (  2 /  ) (  /Z eV) 2 L sun Composition HiRes – protons, Auger- becoming heavier Uncertain interaction cross sections Energy production rate - L B >10 12 L sun & R L =  /eB=40  p,20 kpc  Likely X-Galactic - Consistent with protons,  2 (dQ/d  ) ~ erg/Mpc 3 yr + GZK

UHE CR sources Constraints: - L>10 12 (  2 /  ) L sun -  2 (dQ/d  ) ~ erg/Mpc 3 yr - d(10 20 eV)<d GZK ~100Mpc !! No L>10 12 L sun at d<d GZK  Transient Sources Gamma-ray Bursts (GRBs)  ~ , L  ~ L Sun  L/  2 >10 12 L sun (dn/dVdt)*E~ /Mpc 3 yr * erg ~10 44 erg/Mpc 3 yr Transient:  T  ~10s <<  T p  ~10 5 yr Active Galactic Nuclei (AGN, Steady):  ~ 10 1  L>10 14 L Sun = few brightest !! Non at d<d GZK  Invoke: * “ Dark ” (proton only) AGN * L~ L Sun,  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 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: ] Biased (  source ~  gal for  gal >  gal ) [Kashti & Waxman 08]

The GRB “ GZK sphere ” LSS filaments: D~1Mpc, f V ~0.1, n~10 -6 cm -3, T~0.1keV  B =(B 2 /8  nT~0.01 (B~0.01  G), B ~10kpc Prediction: p  D B [Waxman 95; Miralda-Escude & Waxman 96, Waxman 04]

Summary Galactic  <10 15 eV (<10 19 eV) - L G,CR ~ L G,SN & Max  ~10 15 eV (10 19 eV)  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 (n/1cm 3 ) * Anti-p, e + data consistent with 2 nd ary origin Prediction: e + /(e + + e-)< up to ~300GeV PAMELA  slightly rising f rad (  ) [constrain CR prop. Models] X-Galactic  >10 19 eV - Likely protons,  2 (dQ/d  ) ~ erg/Mpc 3 yr, L B >10 12 L sun  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>100  G, much larger than required for IC explanation of TeV emission (B~10  G). 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 f rad  e + /e - ~  sec ~  -0.5 Or * detailed assumptions RE CR propagation, e.g. isotropic diffusion, D~  , within an  -independent box  f rad ~  (  -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~K 0  , 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/C  sec =[3.2,3.45,3.9] g/cm 2 [green, blue, red]

The eV challenge R B v v 2R  t RF =R/  c) l =R/   22 22 [Waxman 95, 04, Norman et al. 95]

Anisotropy clues: I Galaxy density integrated to 75Mpc CR intensity map (  source ~  gal ) [Waxman, Fisher & Piran 1997] Auger collaboration: Correlation with low-luminosity 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 [Waxman 95, 04] Afterglow, R GRB ~SFR Protons Acceleration/expansion: Synchrotron losses: Proton spectrum: p energy production: 52

GRB Model Predictions [Miralda-Escude & Waxman 96]