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Radio-Loud AGNs as the Sources of the Ultra-High Energy Cosmic Rays. Chuck Dermer (NRL) Naval Research Laboratory, Washington, DC charles.dermer@nrl.navy.mil Recent work with
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Radio-Loud AGNs as the Sources of the Ultra-High Energy Cosmic Rays Chuck Dermer (NRL) Naval Research Laboratory, Washington, DC charles.dermer@nrl.navy.mil Recent work with Matteo Cerruti (CfA), Catherine Boisson (LUTH), Andreas Zech (LUTH), Benoît Lott (CEN Bordeaux), Hajime Takami(KEK), Kohta Murase (IAS) Mid-Atlantic Radio-Loud AGN Meeting, 27 September 2013 , STScI
Observer Leptonic jet model: Nonthermal synchrotron paradigm Associated SSC and EC component(s) Target photon sources: Accretion-disk radiation Broad-line region radiation IR radiation from molecular torus q BLR clouds G Standard Blazar Model Relativistically Collimated Plasma Jet Dusty Torus Five Major Fermi/IACT Blazar Discoveries W Accretion Disk • GeV spectral breaks in FSRQs, LSP/ISP blazars • 3C 454.3 • Rapid variability • Shorter than the BH dynamical timescale • VHE radiation from FSRQs • 3C 279, 4C +21.35, PKS 1510-089 • Two classes of BL Lac objects • Strongly variable (Mrk 421, Mrk 501, PKS 2155-304) • Weaky variable (1ES 0229+200, 0347-121, 1101-232) • EBL/IGMF relationship • Extra component in EBL deabsorbed blazar SED (Finke et al. 2010) • Stecker-Scully relation • Measuring the IGMF SMBH G Ambient Radiation Fields
Equipartition Blazar Modeling • Use log-parabola function for electron distribution • From observations of Lsyn, nsyn, and tvar, derive parameters for B, Doppler factor dD, gpk, r’b • Use numerical model to adjust parameters to fit data, implying energy density of the external radiation field and (minimum) absolute jet power • Constrain location of the g-ray emission site • Explain GeV cutoff in FSRQs and LSP/ISP blazars 3-parameter model: amplitude K, curvature b, gp
Equipartition Relations • Assume (3-parameter) log-parabola function for electron distribution • Use observables and equipartition relations to derive G, B, gp,DR’b log-parabola width gives monoenergetic electron specrum Spectral Relation: What does equipartition mean? Equipartition Relation:
Solution to System of Equations Corrections for b ≠ Minimum jet power Dermer et al. (2012)
FSRQ Modeling 1 GeV Syn vs. EC beaming effect (Dermer 1995)
BL Lac Modeling Similar to SEDs of Mrk 421, Mrk 501, but not PKS 2155-304, 1ES 0229+200, 1ES 1101-232. Contrary to flaring periods in Mrk 501
3C 279 Model Data from Hayashida et al. (2012)
3C 279 Model Data from Hayashida et al. (2012)
Implications • External-fieldenergydensities • Normallyt = 0.1, impliesthatemissionregionnearouteredge of the BLR, ~0.1-0.3 pc from SMBH • Jet Model • Collidingshells • Jet Power • Lessthan Eddington luminosity for MSMBH = (3-8)x108 Mo • ParticleAcceleration • Second-order Fermi acceleration • Extra high-energy spectral component
GeV Spectral Cutoff Explain GeV spectral cutoff by scattering Ly a radiation (Cerruti et al. 2013) Code improvements (Ackermann et al. 2013) (Telfer et al. 2002) Electron distribution (Abdo et al. 2009) gg absorption (Poutanen & Stern 2011) Compton scattering model (Finke & Dermer 2011) Multi-line model Thermal spectrum for dust radiation
Spectral Fits to 3C 454.3 Cerruti et al. (2013) Epoch A: August 2008 low state (Abdo et al. 2009) Epoch B: November 2010 high state(Abdo et al. 2011; Wehrle et al. 2012)
HiRes Collaboration 2008 Auger Collaboration 2009 UHECRs from Radio-Loud AGNs Standard one-zone synchrotron/SSC model Parameters: B, d, R Hillas condition: UHECR sources must satisfy: • Extragalactic • Adequate energy production rate within GZK volume • Sources within GZK radius • UHECRs can escape from acceleration region • Mechanism to accelerate to ultra-high energies Murase, Dermer, Takami, Migliori (2012)
g g Gamma-ray and Cosmic-ray Induced TeV emissionfrom Jetted Sources g e+ g 2g e- Weakly variable cascade radiation lgg g g n,e+ e+ p0, p p g p 2g n,e- e- ~100 Mpc ~ Gpc UHECR protons with energies ~1019 eV make ~1016 eV e that cascade in transit and Compton-scatter CMBR to TeV energies Essey, Kalashev, Kusenko, Beacom (2010, 2011)
Polisensky & Ricotti 2011 Electromagnetic Signatures of UHECRs Photopair-induced cascade in IGM Murase et al. 2012
>10 GeV Sources Explained by Cascade Emission KUV 00311-1938 (z = 0.61) 2 > 100 GeV g-rays within 0.2o Takami, Murase, Dermer 2013 Normalization imposed to fit > 10 GeV Fermi-LAT spectrum from cascade emission • Fermi-LAT analysis • Pass 7 • > 10 GeV • Source class • ROI between 8 and 15 degrees • Use 2FGL source list to remove background sources • g-ray induced cascades • gg/Compton cascade • Use Kneiske et al. (2004) for low and best-fit EBL • Assume no suppression from IGMF ( 10-15 G < BIGMF < 10-20 G) • Intrinsic source spectrum F(Eg) Eg-s , 5.6 GeV < Eg < 100 TeV • UHECR-induced cascade • Bethe-Heitler pair production, photopair production, expansion • UHECR proton sources spectrum: F(Ep) ~ Ep-2.6exp(- Ep/Ep,c), Ep,c =1019eV • Assume no suppression from IGMF (10-10 G < BIGMF for protons)
Predictions for CTA KUV 00311-1938 (z = 0.61) PG 1246+586 (z = 0.847) • KUV 00311-1938 (z = 0.61) • Detected by HESS at 5.1s with 52.5 hrs observation (Stegmann 2012) • Lg > 3.5x 1046 erg/s • LUHECR >1.1 x1047 erg/s • PG 1246+586 (z = 0.847) • Not yet detected by TeV instrument • Lg > 7.5x1046 erg/s • LUHECR >2.0x1047 erg/s • Other sources detectable by 50 hour observations with CTA in the Neronov et al. (2012) list are Ton 116, B3 1307+433, 4C +55.17, and PKS 1958-179.
Pair Production and Photohadronic Opacity in 4C +21.35 Inject ultra-relativistic leptons: Dermer, Murase, Takami (2012) Make synchrotron g-rays Detection of 40-700 GeV g rays x >> 0.1pc →←
Modeling New equipartition technique for fitting blazar SEDs Fits to 3C 279 Emission region at outer edge of BLR Explain GeV cutoffs of 3C 454.3 UHECRs: Blazars are the likely source of UHECRs, as can be tested with CTA UHECRs from blazars would explain extra high-energy spectral components Stecker-Scully relation, weakly variable BL Lac class VHE g-ray production in FSRQs Summary Dermer MARLAM 26 September 2013
EBL Effects on Blazar Spectra Dermer et al. 2011 • GeV-TeV Spectral Index Difference DGStecker-Scully (2006, 2010) relation • Measurements of IGMF (>~ 10-15 G for persistent jet; >~10-18 G for jet active for observing period) Origin of hard component in deabsorbed BL Lac spectra? GeV spectral breaks in FSRQs, LSP/ISP blazars Rapid variability Two classes of BL Lac objects VHE radiation from FSRQs EBL/IGMF relationship
Fermi Observations of 4C+21.35 PKS 1222+2163 = 4C+21.35, z = 0.432 Fermi-LAT spectrum Fermi LAT observations • Major flares 2010 April and June • sub-day scale variability • hour-scale variability (Foschini et al. 2011) • nFn peak at 1 – 10 GeV 22
GeV-TeV Connection Neronov et al. 2012 • 21 joint GeV-TeV sources Abdo et al. (2009) • 46 Extragalactic Sources listed in the VHE sky Wagner’s catalog • Neronov et al. (2012) source catalog of 13 candidates of VHE emission at z > 0.5 • EBL effects greater on more distant blazars • tgg(Ec,z) = 1 at Ec≈ 100 GeV/z for 0.03 < z < 3 • Model the >10 GeV Fermi-LAT emission by cascade grays vs. cascades induced by UHECRs • Find minimum required jet powers and predictions for CTA
Five Big Fermi/IACT Blazar Discoveries LBAS, Abdo et al. 2009 • GeV spectral breaks in FSRQs, LSP/ISP blazars • Rapid variability • VHE radiation from FSRQs • Two classes of BL Lac objects • EBL/IGMF relationships
Five Big Fermi/IACT Blazar Discoveries 3C 454.3 Abdo et al. 2009 GeV spectral breaks in FSRQs, LSP/ISP blazars Rapid variability VHE radiation from FSRQs Two classes of BL Lac objects EBL/IGMF relationship Ackermann et al. 2010
Five Big Fermi/IACT Blazar Discoveries MAGIC observations of Mrk 501 2005 July 9 Feb 2010 VERITAS OBS of MRK 421, Albert et al. 2007 • GeV spectral breaks in FSRQs, LSP/ISP blazars • Rapid variability • Two classes of BL Lac objects • VHE radiation from FSRQs • EBL/IGMF relationships
Five Big Fermi/IACT Blazar Discoveries HESS obs. of PKS 2155-304 RS/c = 104M9 s tvar ~ 5 min = 300 s (?) M << 108 M0 28 July 2006 flare Aharonian et al. 2007 • GeV spectral breaks in FSRQs, LSP/ISP blazars • Rapid variability • Two classes of BL Lac objects • VHE radiation from FSRQs • EBL/IGMF relationship
Five Big Fermi/IACT Blazar Discoveries 3C 454.3 Ackermann et al. 2010 GeV spectral breaks in FSRQs, LSP/ISP blazars Rapid variability Two classes of BL Lac objects VHE radiation from FSRQs EBL/IGMF relationship
MAGIC Observations of PKS 1222+2163 = 4C+21.35 z = 0.432, flare of 17 June 2010 MAGIC spectrum MAGIC observations • Emission over 30 minutes • Flaring on timescales of 10 minutes • Lg ~ 1047 erg/s (TeV energies) • Lg ~ 1048 erg/s (GeV energies) Black hole mass: 1.5x108 Mo (Wang et al. 2004) extreme MAGIC light curve G = 3.7 Fermi-LAT and MAGIC spectrum Aleksic et al. (2011) Tanaka et al. (2011)
Five Big Fermi/IACT Blazar Discoveries Mrk 421 Abdo et al. 2011a • Variable class • Mrk 421, Mrk 501 • PKS 2155-305 • 0716+714, etc. • Extreme sources • tvar < RS/c Mrk 501 Abdo et al. 2011b GeV spectral breaks in FSRQs, LSP/ISP blazars Rapid variability Two classes of BL Lac objects VHE radiation from FSRQs EBL/IGMF relationship
Five Big Fermi/IACT Blazar Discoveries Mrk 421 Mrk 421 Mrk 421 tv = 4 d Abdo et al. 2011a B′=0.015G, d=12, R′=1.3x1017 cm Abdo et al. 2011a Abdo et al. 2011a • Variable class • Mrk 421, Mrk 501 • PKS 2155-305 • Extreme sources • tvar < RS/c • SSC Model fits time-averaged emission B′=0.038G, d=21, R′=5.2x1016 cm Mrk 501 Mrk 501 Mrk 501 tv = 1 d Abdo et al. 2011b Abdo et al. 2011b Abdo et al. 2011b GeV spectral breaks in FSRQs, LSP/ISP blazars Rapid variability Two classes of BL Lac objects VHE radiation from FSRQs EBL/IGMF relationship
TeV BL Lac Objects Mrk 421 Tavecchio et al. 2011 1ES 0229+200 z = 0.14 1ES 0347-121 z = 0.186 1ES 1101-232 z = 0.14 1ES 0548-322 z = 0.069 RGB J0152+0.17 z = 0.08 Abdo et al. 2011b Compton-scattered CMBR from extended jet/lobe Albert et al. 2007 Böttcher et al. 2008 • Highly variable class • Extreme sources • tvar < RS/c • SSC Model fits • Large inferred G factors • Weakly variable class • Weak Fermi LAT fluxes • GeV-TeV spectrum: EBL, IGMF
VHE g rays from FSRQs Senturk et al. 2013 And PKS 1510-089 With HESS and MAGIC GeV spectral breaks in FSRQs, LSP/ISP blazars Rapid variability Two classes of BL Lac objects VHE radiation from FSRQs EBL/IGMF relationship