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Solution to the Problem of UHECR Origin

UHECR Accelerators in Gamma Ray Bursts and Blazars Chuck Dermer Naval Research Laboratory, Washington, DC, USA Armen Atoyan Concordia University, U. de Montr é al, Montreal, CA International Astroparticle Physics Symposium Golden, Colorado May 6-8, 2008.

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Solution to the Problem of UHECR Origin

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  1. UHECR Accelerators in Gamma Ray Bursts and BlazarsChuck DermerNaval Research Laboratory, Washington, DC, USAArmen Atoyan Concordia University, U. de Montréal, Montreal, CAInternational Astroparticle Physics SymposiumGolden, Colorado May 6-8, 2008

  2. Solution to the Problem of UHECR Origin • UHE n Sources (Cosmogenic Neutrinos) • Cosmic Ray Arrival Directions • g-ray Sources: Evidence for Hadronic Emissions • Astrophysical Evidence Source Morphology Sources within GZK radius Plausible Acceleration Scenario Energetics and Power Neutral Beam Model for UHECR Origin Atoyan and Dermer (ApJ, 2003; PRL 2001, 2003,…)

  3. Extragalactic Gamma Ray Sources GRBs 270 EGRET sources (3EG) 5 Spark Chamber GRBs 70 High Confidence Blazars LMC, Cen A, NGC 6251 (?; see Mukherjee et al. 2002) >20 TeV blazars, radio galaxy M87

  4. GRBs Multiple Classes 1. Long duration GRBs 2. X-ray flashes 3. Short Hard Class of GRBs 4. Low-luminosity GRBs GRB 980425, d  40 Mpc GRB 030329, d  800 Mpc GRB 060218, d  145 Mpc Long Duration GRBs Found in Star Forming Galaxies GRB/Supernova connection Collapse to Newly Formed Black Hole Prompt phase: internal or external relativistic shocks Afterglow phase: external shock Mean redshift: ~1 (BATSE), ~2 (Swift) Short hard GRBs Long soft GRBs Kouveliotou et al. 1993

  5. Radio Galaxies and Blazars Cygnus A FR2/FSRQ L ~1045 x (f/10-10 ergs cm-2 s-1) ergs s-1 Mrk 421, z = 0.031 FR1/BL Lac 3C 279, z = 0.538 L ~5x1048 x (f/10-9 ergs cm-2 s-1) ergs s-1 FR1/2 dividing line at radio power 1042 ergs s-1 3C 296 BL Lacs: optical emission line equivalent widths < 5 Å

  6. Energetics and Power

  7. UHECR Emissivity Yamamoto et al. (2007) 1020 0.4 1019 1.3 1018 3.5 1017 40

  8. GRB X-ray/g-ray Emissivity GRB fluence: > 20 keV fluence distribution of 1,973 BATSE GRBs (477 short GRBs and 1,496 long GRBs). 670 BATSE GRBs/yr (full sky) Vietri 1995; Waxman 1995 (independent of beaming) Baryon loading (Band 2001)

  9. Blazar g-ray Emissivity >100 MeV g-Ray fluence: (Dermer 2007)

  10. Relativistic Blast Wave Model for GRBs and Blazars Nonthermal g rays  nonthermal particles + intense photon fields • Leptonic blast wave model: optical/X-rays/soft g-rays are nonthermal lepton synchrotron • Hadronic blast wave model: • Photomeson production second g-ray component (Buckley 1999)

  11. Acceleration to UHE • Relativistic external shock acceleration inefficient • First-order acceleration in mildly relativistic shocks of colliding shells • Second-order Fermi (stochastic) acceleration Shocked shell width: Hillas condition (rL< R): Magnetic field in blast wave shell: x At deceleration radius x = xd: G

  12. Electrodynamic Argument for UHECR Acceleration Waxman’s argument: GRBs: x Blazars: G

  13. UHECRs from GRBs

  14. Gamma-Ray Bursts as Sources of High-Energy Cosmic Rays Inject -2.2 UHECR protons to E > 1020 eV Injection rate density determined by GRB formation rate (= SFR?) GZK cutoff from photopion processes with CMBR Ankle by pair production effects (Wick, Dermer, and Atoyan 2004)

  15. Star Formation Rate: Astronomy Input Hopkins & Beacom 2006 Fitting Redshift and Opening-Angle Distribution SFR6, pre-Swift SFR6, Swift SFR6, pre-Swift Le & Dermer 2006

  16. UHECR Protons from GRBs: Effects of Different SFRs

  17. Leptonic GRB Modeling • Dominant synchrotron radiation at X-g energies • Two peaks in nFn distribution • Power-law afterglow decay • Generic rise in intensity until tdec, followed by constant or decreasing flux (except in self-absorbed regime or in synchrotron/SSC trough) E=1054 ergs n0=100 cm-3 eB = 10-4 • nFn spectra shown at 10i seconds after GRB • gg opacity included

  18. Anomalous g-ray Emission Components in GRBs Long (>90 min) g-ray emission (Hurley et al. 1994)

  19. Anomalous High-Energy Emission Components in GRBs Evidence for Second Component from BATSE/TASC Analysis −18 s – 14 s 1 MeV 100 MeV 14 s – 47 s 47 s – 80 s Hard (-1 photon spectral index) spectrum during delayed phase 80 s – 113 s 113 s – 211 s GRB 941017 (González et al. 2003)

  20. Proton Injection and Cooling Spectra GRB synchrotron fluence Nonthermal Baryon Loading Factor fb = 30 Injected proton distribution Cooled proton distribution Forms neutral beam of neutrons, g rays, and neutrinos Escaping neutron distribution

  21. Photohadronic Cascade Radiation Fluxes Photomeson Cascade Nonthermal Baryon Loading Factor fb = 1 Ftot = 310-4 ergs cm-2 C3 S1 Total emits synchrotron (S1) and Compton (C1) photons emits synchrotron (S2) and Compton (C2) photons, etc. C2 S2 C4 S3 S4 C5 S5 Photon index between −1.5 and −2 Fits data for GRB 941017 spectrum during prompt phase MeV C1 d = 100

  22. Photon and Neutrino Fluence during Prompt Phase Hard g-ray emission component fromhadronic-induced electromagnetic cascade radiationinside GRB blast wave Second component from outflowing high-energy neutral beam of neutrons, g-rays, and neutrinos Nonthermal Baryon Loading Factor fb = 1 Ftot = 310-4 ergs cm-2 d = 100

  23. Neutrinos from GRBs in the Collapsar Model requires Large Baryon-Loading Nonthermal Baryon Loading Factor fb = 20 (~2/yr) Dermer & Atoyan 2003

  24. GZK neutrinos from UHECRs produced by GRBs Barwick et al. 2006

  25. UHECRs from Radio Galaxies and Blazars

  26. Leptonic Blazar Modeling Temporally evolving SEDs Evolution of electron distribution with time: information about acceleration (e.g., loop diagrams); Correlated behavior from leptonic emissions Infer B field, Doppler power, jet power, location z = 0.538 Böttcher et al. 2007 L ~5x1048 x (f/1014 Jy Hz) ergs s-1

  27. Evidence for Anomalous g-Ray Components in Blazars Orphan TeV flares 1ES 1959+650 Krawczynski et al. 2004 Böttcher 2005

  28. Photo-hadronic Blazar Jet Models Possible photon targets forp +: • Internal:synchrotron radiation (Mannheim & Biermann 1992, Mannheim 1993) requires a compact jet: nphot()  Lsyn/Rjet2 target disappears with jet expansion on: t ' ~ R'jet/c ~ tvar/(1+z) • External:accretion disk radiation (UV) (i)direct ADR:(Bednarek & Protheroe 1999) anisotropic, effective up to R < 100 Rgrav < 0.01 pc (ii) ADR scattered in the Broad-Line region (Atoyan & Dermer 2001) quasi-isotropic,up toRBLR~ 0.1-1 pc • Impact of the external ADR component: high p-rates & lower threshold energies: protMeV/(1- cos) =7 (solid) =10 (dashed) =15 (dot-dashed) (red - without ADR) (for 1996 flare of 3C 279)

  29. Blazars as High Energy Hadron Accelerators Powerful blazars / FR-II Neutrons with En > 100 PeV and rays with E > 1PeV take away ~ 5-10 %of the total WCR(E > 1015eV=1 PeV) injected at R<RBLR (3C 279) Synchrotron and IC fluxes from the pair-photon cascade for the Feb 1996 flare of 3C279 dotted -CRs injected during the flare; solid - neutrons escaping from the blob, dashed -neutrons escaping from Broad Line Region (ext. UV) dot-dashed -g rays escaping external UV field (produced by neutrons outside the blob) 3dot-dashed- Protons remaining in the blob atl = RBLR astro-ph/0610195 Sreekumar et al. (1998)

  30. Hadronic Emission Components in Blazars

  31. UHE neutrons &  -rays: energy & momentum transport from AGN core • UHE -ray pathlengths in CMBR: l~ 10 kpc - 1Mpc for En ~ 1016 - 1019 eV • Neutron decay pathlength: ld(n) = 0 c n(0 ~ 900 s)  ld ~ 1 kpc - 1Mpc for E ~ 1017 - 1020 eV solid: z = 0 dashed: z = 0.5 Detection of single high-energy n from blazars  neutral beams could power large-scale jets

  32. Pictor A d ~ 200 Mpc l jet ~ 1 Mpc (lproj = 240 kpc) Deposition of energy through ultra-high energy neutral beams (Atoyan and Dermer 2003) Pictor A in X-rays and radio(Wilson et al, 2001 ApJ 547)

  33. Neutrinos: expected fluences/numbers Expected  - fluences calculated for 2 flares, in 3C 279 and Mkn 501, assuming proton aceleration rateQprot(acc) = Lrad(obs) ;red curves- contribution due to internal photons, green curves - external component (Atoyan & Dermer 2003) Expected numbers of for IceCube-scale detectors, per flare: • 3C 279: N = 0.35 for  = 6 (solid curve) and N = 0.18 for  = 6 (dashed) Mkn501: N = 1.210-5 for  = 10 (solid) and N = 10-5for  = 25 (dashed) (`persistent')  -level of 3C279 ~ 0.1 F (flare) , ( + external UV for p ) N ~ few - several per year can be expected from poweful HE  FSRQ blazars. N.B. : all neutrinos are expected at E>> 10 TeV

  34. UHECR protons from GRBs and Radio-Loud AGNs • Why (these) Black Holes? • UHECRs from GRBs • Low luminosity GRBs in the local universe • g-ray signatures of UHECR acceleration • Detectable neutrino emission from large fluence GRBs with km-scale neutrino detectors • Diffuse GZK neutrino spectrum measures UHECR source SFR • Neutron-decay halos • UHECRs from Blazars and Radio Galaxies • Detectable PeV neutrinos from bright (FSRQ) blazar flares • Linear jets • Association of UHECR arrival directions with Cen A • GLAST should detect anomalous g-ray components from UHECR sources Summary

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