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Leptonic Blazar Model Overview

Beamed and Unbeamed Gamma-Rays from Galaxies Hotel Olos, Finland 12 April 2011. Leptonic Blazar Model Overview. Blazar sequence Black hole engine: accretion vs. rotation power Synchrotron/SSC model: TeV (HSP) BL Lacs and FR1 radio galaxies Unification Variability

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Leptonic Blazar Model Overview

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  1. Beamed and Unbeamed Gamma-Rays from Galaxies Hotel Olos, Finland 12 April 2011 Leptonic Blazar Model Overview • Blazar sequence • Black hole engine: accretion vs. rotation power • Synchrotron/SSC model: TeV (HSP) BL Lacs and FR1 radio galaxies • Unification • Variability • 4. EC models – break in FSRQ GeV spectrum • 5. Spectral fitting of TeV blazars and the IGMF (1ES 0229+200) • BIGMF >10-18 G • Additional spectral component with nFn peak > 1 TeV • EBL Chuck Dermer Naval Research Laboratory Washington, DC USA charles.dermer@nrl.navy.mil (g ray perspective) Dermer Gamma-Ray Galaxies Workshop 11-14 Apr 2011

  2. Selection Biases • red: FSRQ • cyan: LSP BL Lac • gray: ISP BL Lac • blue: LSP BL Lac • magenta: radio galaxies + others z = 0.2 1.0 0.5 • Photon index = 2 is vFv peak • Spectral change at • Lg ~ 1046 erg s-1 • Fermi Blazar Divide: change in accretion regime? (Ghisellini et al. 2009) • Construct diagram for X-ray, TeV … wavebands Abdo et al. (2010) (1LAC) Gamma Ray Galaxies, Lapland (100 MeV – 100 GeV)

  3. Misaligned Radio Galaxies and Blazars • Core vs. lobe dominance • Unification • Two classes of g-ray galaxies: 1. blazar/radio galaxies 2. starburst/star-forming (or 3? cf. Dermer & Gehrels 1995: soft vs. medium g rays) • Where are the shocks? Abdo et al. (2010) (MAGN) Cen A Lobes with Fermi Abdo et al., Science, 2010 Spectral Index Abdo et al. 2010 (starbursts) Rotation/black-hole-powered SNR-powered

  4. Blazar Sequence • Inverse correlation between Epeak and luminosity (Fossati et al. 1998) • Selection/incompleteness biases (Giommi et al. 1999; Padovani et al. 2003, Padovani 2007) • Cooling model with external radiation for FSRQs (Ghisellini et al. 1998) • Physical model for sequence • Galaxy evolution through reduction of fuel from surrounding gas and dust (Böttcher and Dermer 2002) • BZ effect and galaxy evolution • (Cavaliere and d’Elia 2002) Where do RLNL Sy 1s fit in? PMN J0948+0022 z=0.585 GeV TeV Abdo et al. 2009, ApJ, 699, 976 (scale in units of LEdd) Foschini et al. (2009)

  5. Black-hole engine • Accretion vs. black hole rotation as main source of energy? • Mechanisms for collimation Event horizons Ergosphere radius (thanks to Maxim Barkov)

  6. Black-hole engine • Accretion vs. black hole rotation as main source of energy? • Mechanisms for collimation Radiant accretion luminosity: Lrad = ℓEdd LEdd 1047 M9ℓEdderg/s ℓEdd includes mass accretion rate and radiant luminosity Eddington luminosity LEdd

  7. Black-hole engine • Accretion vs. Black Hole Rotation as main source of energy? • Mechanisms for collimation Radiant accretion luminosity: Lrad = ℓEdd LEdd 1047 M9ℓEdderg/s ℓEdd includes mass accretion rate and radiant luminosity Eddington luminosity LEdd Blandford-Znajek power: collimating geometry?

  8. Blandford-Znajek Process • Find solutions for steady state magnetosphere Condition of a force-free axisymmetric magnetosphere  With Znajek regularity condition Angular velocity of the event horizon Levinson 2006 Dermer & Menon 2009

  9. Hypothesis/guess • Extraction of energy through black-hole rotation collimates jet outflow with • Implies beaming factor • Jet opening angle

  10. 3C 454.3 (Abdo et al. 2011, Nov11 flare, ApJ in press) • Reached apparent isotropic luminosities of 2×1050 erg/s • Black hole mass estimates: 0.5 < M9 < 4 (Bonnoli et al. 2010) • Therefore Lg,iso/LEdd >~ 1000  a/M > 0.999 Gmin 14 from gg opacity arguments Smaller value of a/M for BL Lac objects?

  11. PKS 2155-304 • X-ray selected BL Lac; z = 0.116, dL = 540 Mpc • August 2006: bright flares, detected by • Swift (Foschini et al. 2007) (3 ks/day) • HESS (Aharonian et al. 2007) • TeV variability timescale: ~5 minutes Also Mrk 501 (with MAGIC; Albert et al. 2007) Mrk 421 2010 flare

  12. gg opacity and Gmin for PKS 2155-304 Lower EBL • Radio galaxy core emission well fit by sync./SSC model with d  G  few (e.g., Cen A, M87, NGC 1275, NGC 6251) • The d-unification problem -- Decelerating Jet Model (Georganopoulos & Kazanas 2003) -- Spine and Sheath Model (Ghisellini et al. 2005) -- Colliding Shell Model (Saas Fee lecture, in preparation) Standard one-zone synchrotron/SSC model (e.g., Finke et al. 2008) 3 parameters: B, d, R (g′min = 100 ) Doppler factor d >> 100 during flaring episodes (d > 60 from gg opacity arguments; Begelman et al. 2008)

  13. The Peculiarly Constant GeV Spectral Break in 3C 454.3 νFν for MJD=55152-55261 MJD=55280-55300 Fit : BPL, LogPar, Expcutoff No strong evolution of Eb is found Abdo et al. (2010) (talk by B. Lott on Thursday) Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  14. Models for Spectral Break Intrinsic spectral break in electron energy distribution with Compton-scattered accretion disk and broad line region radiation (Finke & Dermer 2010) Robust solution, independent of dissipation radius, within BLR with wind-density (disk-wind) gg attenuation from H (13.6 eV) and He II (54.4 eV) recombination radiation deep within the BLR (Poutanen & Stern 2010) Finke and Dermer (2010) Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  15. Models for Spectral Break Intrinsic spectral break in electron energy distribution with Compton-scattered accretion disk and broad line region radiation (Finke & Dermer 2010) Robust solution, independent of dissipation radius, within BLR with wind-density (disk-wind) gg attenuation from H (13.6 eV) and He II (54.4 eV) recombination radiation deep within the BLR (Poutanen & Stern 2010) Finke and Dermer (2010) Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  16. Break due to Compton-Scattered Ly a Radiation? Bonnoli et al. (2009) GALEX and UVOT observations of strong Ly a: 2×1045 erg s-1 Emission region size from reverberation mapping studies  Energy density of BLR Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  17. Break due to Compton-Scattered Ly a Radiation? Bonnoli et al. (2009) GALEX and UVOT observations of strong Ly a: 2×1045 erg s-1 Emission region size from reverberation mapping studies  Energy density of BLR Use log-parabola? Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  18. Origin of the Intergalactic Magnetic Field (BIGMF): Primordial Early universe physics Biermann battery Galaxy dynamo other Measurement of the Intergalactic Magnetic Field BIGMF Recombination inflation Electroweak IES 0229+200 QCD IES 0347-121 Gamma Ray Galaxies, Lapland Neronov & Vovk (2010)

  19. Geometry for Compton-gg Cascade Apply to 1ES 0229+200 z = 0.1396  0.14 Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  20. TeV Data VERITAS data preliminary Aharonian et al. 2007 Perkins et al. 2010 E (TeV) Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  21. GeV/TeV Data Marginal Fermi LAT detection: Orr, Krennrich, Dwek 2011 Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  22. Semi-analytic Model of Cascade Pair injection from EBL absorption CD, Cavadini, Razzaque, Finke, Chiang, Lott 2011 kinematic term cascade g(Dteng): time for electrons to cool to g during activity time Dteng of central engine g at which electrons are deflected out of beam Compton (Thomson) spectrum from cooling electrons

  23. tgg and lgg 1ES 0229+200 z  0.14

  24. Persistent Jet Emission Hypothesis (Neronov & Vovk 2010; Tavecchio et al. 2010, Dolag et al. 2011) qj = 0. 1 Gamma Ray Galaxies, Lapland

  25. qj = 0. 3 Pair halos: Ando & Kusenko 2010; Neronov et al. 2010 Halo emission more pronounced for large opening angle, persistent jets Gamma Ray Galaxies, Lapland

  26. qj = 1.0 Limit on qj ~< 0.4 for persistent TeV jets Gamma Ray Galaxies, Lapland

  27. Jet activity for time tengine: BIGMF = 10-19 G qj = 0. 1 Finke et al. (2010) EBL model

  28. Jet activity for time tengine: BIGMF = 10-18 G tengine = 3162 yr tengine = 1 yr Gamma Ray Galaxies, Lapland

  29. Cascade for different BIGMF Gamma Ray Galaxies, Lapland

  30. Cascade spectrum for different deabsorbed source spectrum Note TeV feature for strong source flux (also found In numerical results; Dolag et al. 2011)  BIGMF > 10-18 G Gamma Ray Galaxies, Lapland

  31. Notes • Origin of spectral component peaking at >TeV energies Synchrotron/SSC models imply large dD If EC, require low-energy target photon source (e.g. CMB): weakly variable TeV emission (Böttcher et al. 2008) Photo-pair generated cascade from UHECRs Essey, Kusenko, Beacom et al. 2010, 2011 2. Impact of EBL model on conclusions

  32. EBL Models (courtesy of Justin Finke)

  33. z = 0.047 z = 0.044 z = 0.129 z = 0.139 z = 0.186 z = 0.188 z = 0.44 z = 0.538 Gamma Ray Galaxies, Lapland Finke et al. (2010)

  34. z = 0.047 z = 0.044 z = 0.129 z = 0.139 z = 0.186 z = 0.188 variable z = 0.44 z = 0.538 Gamma Ray Galaxies, Lapland

  35. Gamma Ray Galaxies, Lapland

  36. Invalid > 10 TeV

  37. Leptonic Models: Summary • Black hole energization • Blazar sequence • Spectral breaks in FSRQs • New primary spectral component peaking at >> TeV energies • synchrotron/SSC makes double-humped spectrum with cascade radiation  weak BIGMF Synchrotron/SSC models incomplete without the addition of the cascade component (or statement of minimum BIGMF) • Photopion-generated emission from UHECRs or extended jet emission is non- or weakly variable • Any other way for leptons to emit distinct TeV emission component? • Hadronic processes in TeV BL Lacs? (more likely if they are sources of UHECRs) Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  38. Conclusions • Large range of primary source spectra match data • Minimalist model implies BIGMF >~ 10-18 G • All require an emission component with nFn peak >~ 5 TeV • Question: Origin of this spectral component? • Leptonic or hadronic (UHECR?) • Spectral shoulder at 1 TeV implies hard primary emission • Halo emission likely for large opening angle, persistent TeV jet sources Gamma-Ray Galaxies Workshop, Finland, April 11-15, 2011

  39. Local (z<<1) MFPs for electron energy loss and gg attenuation Gamma Ray Galaxies, Lapland

  40. Evidence of UHECRs? • New component could be leptonic or hadronic • Must explain dependence of break energy on z Böttcher et al. 2008: Leptonic Model for 1ES 1101-232

  41. CTA Beamed and Unbeamed Gamma-Rays from Galaxies somewhere above the Arctic circle, Lapland, Finland April 12, 2011 Leptonic Blazar Model Overview Beginning with the simplest relativistic jet synchrotron/SSC model and its application to analysis of the SEDs of radio-loud AGN,  I consider complications of internal photon opacity, gamma-ray absorption and reprocessing in the EBL, and more complicated shell geometries. Questions about the rapid variability in PKS 2155-304 and Mrk 501 are addressed in terms of unification scenarios between BL Lacs and FR1 radio galaxies. The addition of external soft photons forms the external Compton gamma-ray component thought to account for the gamma-ray luminous FSRQs. I conclude with questions of the location of the gamma-ray emission site and the validity of and explanations for the blazar sequence. Chuck Dermer Naval Research Laboratory Washington, DC USA charles.dermer@nrl.navy.mil

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