1. Radio Quiet AGNs as possible sources of UHECRs Based on work by Asaf Pe’er (STScI), Kohta Murase (Yukawa Inst.) & Peter Mészáros (PSU) October 2009 Phys. Rev. D, submitted

2. What do we know about sources of UHECRs ? Acceleration time <~ dynamical time No anisotropy towards galactic center Acceleration time <~ synchrotron cooling time Likely Extra-Galactic Within the GZK horizon B-field at the acceleration site is not more than few G “Acceleration efficiency” Zq = charge ; Am p = mass

3. “Classical” sources Restrictive limitation on source Luminosity: Gamma-ray Bursts (GRBs, transient)  ~ 10 2.5, L  ~ 10 51 erg/s  L/  2 >10 12 L sun (Radio loud) Active Galactic Nuclei (AGN, Steady):  ~ 10 1, L~10 45- 10 46 erg/s ; few brightest But - Non at d<d GZK  * “ Dark ” (proton only) AGN * “ Giant flares ” L~ 10 14 L Sun,  t~1month flares

4. UHECR composition Unger+07 Bellido+09 PAO results hint towards heavy composition at very high energy -> Releases the Luminosity requirement Heavy nuclei -> many more plausible sources !

5. 1.Photo-pair production: N +  -> N+ e + e -  th ~ 1MeV ;  ~5*10 -31 (Z 2 /A) cm 2 2.Photo-pion production: N +  -> N +  0  th ~ 145 MeV ;  ~7*10 -29 cm 2 3.Nuclear spallation t sp -1 =  sp nc ; depend on the number density 4.Photo-disintegration (most important) - depends on photon spectrum  th ~ 10 MeV ; Energy loss channels of energetic heavy nuclei

6. MRK586 Elvis + 94 Spectra of radio quiet AGNs Richards+06 Approximate spectrum as broken power law, n(  )~  0 ( <10 13 Hz) n(  )~  -2 ( >10 13 Hz)

7. Survival condition for photo-disintegration Conclusion: heavy nuclei survive photo-disintegration if acceleration occurs on pc-scale

8. VLBA obs. of NCG3079 (Middelberg+07) VLBA image of NGC4151 (Ulvestad+05) Observations: weak, pc-scale jets in RQ AGNs Shock waves expected on this scale ! (Possible acceleration sites)

9. (Dermer, ICRC07) Efficiency in UHECR production Observed flux: J(>10 19.5 eV) ~ 5*10 -16 m -2 s -1 sr -1 GZK horizon - similar for heavy nuclei and protons, ~100 Mpc Total energy prod. rate - Density of RQ AGNs in local universe -  42 ~10 -3 Mpc -3 (10X  RL AGNs ) Energy prod. rate of UHECRs in a single source - Energetically consistent

10. Consequences  No / weak correlation between arrival direction of UHECRs and radio loud AGNs (but not excluded !)  Dominate process - photodisintegration ; - No copious production of  ’s ; - No strong ’s signature from RQ AGNs  Heavy nuclei composition: - hint towards AGNs sources (disfavors GRBs)

11. Heavy nuclei composition of UHECRs opens window to new sources  RQ AGNs are plausible sources of UHECRs, provided acceleration occurs at ~pc scale.  - Consistent with recent observations of weak jets.  Energy requirement: ~1 % for UHECRs;  Main energy loss channel - photodisintegration - No copious production of ’s  No strong correlation with RL AGNs Summary