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Blazar jet physics in the age of Fermi

Jets at all Scales International Astronomical Union Symposium No. 275 Buenos Aires, Argentina, 13-17 September, 2010. Blazar jet physics in the age of Fermi. Soebur Razzaque (NRL) Justin Finke (NRL). Charles Dermer United States Naval Research Laboratory Washington, DC USA

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Blazar jet physics in the age of Fermi

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  1. Jets at all Scales International Astronomical Union Symposium No. 275 Buenos Aires, Argentina, 13-17 September, 2010 Blazar jet physics in the age of Fermi Soebur Razzaque (NRL) Justin Finke (NRL) Charles Dermer United States Naval Research Laboratory Washington, DC USA charles.dermer@nrl.navy.mil On behalf of the Fermi Collaboration and Outline 1. Fermi Gamma ray Space Telescope 2. Blazars with Fermi 3. FSRQs: 3C 454.3: origin of GeV spectral break 4. BL Lac: PKS 2155-304 and Gmin 5. EBL, Halos, and the Intergalactic Magnetic Field 6. Are blazars UHECR sources? Evidence from Fermi Dermer Buenos Aires, Argentina 13-17 September 2010

  2. Fermi instruments Large Area Telescope (LAT): 20 MeV  300 GeV (including unexplored 10-100 GeV range) 2.4 sr FoV (scans entire sky every ~3 hrs) • Gamma-ray Burst Monitor (GBM) • 8 keV - 40 MeV • 12 NaI detectors (8 keV - 1 MeV)‏ • onboard trigger, onboard and ground localizations, spectroscopy • 2 BGO detectors (0.15 - 30 MeV)‏ • spectroscopy • views entire unocculted sky • No consumables Dermer Buenos Aires, Argentina 13-17 September 2010

  3. e– e+ Overview of the LAT • Precision Si-strip Tracker (TKR) Measure the photon direction; gamma ID • Hodoscopic CsI Calorimeter (CAL)Measure the photon energy; image the shower • Segmented Anticoincidence Detector (ACD)Reject background of charged cosmic rays; segmentation removes self-veto effects at high energy • Electronics SystemHardware trigger, software filters Tracker ACD Calorimeter Dermer Buenos Aires, Argentina 13-17 September 2010

  4. FR1/2: radio power/morphology correlation; dividing line at  4×1040 ergs s-1(2×1025 W/Hz at 178 MHz) Radio Galaxies and Blazars Cygnus A 3C 279 BL Lacs vs. FSRQs: EW < 5 Å Ca H-K break < 0.4 (lmax −lmin)/lmax > 1.7 FR2  FSRQ Mrk 501, z = 0.034 3C 279, z = 0.538 FR1  BL Lac 3C 296 W Comae (talk by M. Hayashida) BL Lac vs. FSRQ RQ vs. RL Blazar Unification: Padovani & Urry (1995) Dermer IAU 275 17 September 2010

  5. Fermi AGNs • LAT Bright AGN Sample (LBAS); First year LAT AGN Catalog (1LAC) LBAS: 3 month source list: 2008 Aug 4 – Oct 30 1LAC: 1 year catalog: 2008 Aug 4 – 2009 July 4 3EG (EGRET): 10 >10s |b|>10 sources 66 >5s blazars LBAS: subset of 0FGL w/ 205 sources TS >100 (>10s) 106 |b|>10 sources assc. w/ AGNs 1FGL TS >25 1451 sources 1043 |b|>10 sources 1LAC TS >25 (> 4.1s) 671 assc. w/ 709 AGN (663 hi-conf. associations) (300 BL Lacs, 296 FSRQ, 41 other AGN, 72 unknown) 1 year Fermi GeV sky Dermer IAU 275 17 September 2010

  6. Classifying Fermi AGNs Abdo et al. 2010, ApJ, 710, 1271 • Radio: FR1 vs FR2 • Optical: FSRQs vs. BL Lacs • SED; (“synchrotron-peaked”) LSP (npksyn < 1014 Hz), HSP (npksyn > 1015 Hz) ISP LSP PKS 1510-089 Essentially all FSRQs are LSPs HSP Mrk 421 Dermer IAU 275 17 September 2010

  7. Spectral Index Distribution PKS 1510-089 z = 0.361 Dermer IAU 275 17 September 2010

  8. Properties of 1st LAT AGN Catalog (1LAC) • Small number of non-blazar sources • 6 RG, 3 starburst (incl. NGC 4945), 2 SSRQs, 5 NLRGs, 10 RQ • Redshift distributions peaking at z 1 FSRQs, at low redshift for BL Lacs • But…only 121 out of 291 1LAC BL Lacs have measured redshifts • A high BL Lac/FSRQ ratio, close to unity • A high HSP/LSP ratio among BL Lacs • Strong correlation between photon spectral index and blazar class Dermer IAU 275 17 September 2010

  9. Complex GeV Spectral Behavior • Sampling separate FSRQ and BL Lac populations Abdo et al. (2009) LBAS Dermer IAU 275 17 September 2010

  10. Misaligned Radio Galaxies • Spectral change at Lg ~ 1046 erg s-1 • Fermi Blazar Divide: change in accretion regime? (Ghisellini et al. 2009) Abdo et al. (2010) (MAGN) Cen A Lobes with Fermi Abdo et al., Science, 2010 Dermer IAU 275 17 September 2010

  11. Understanding the Blazar Sequence • Inverse correlation between Epeak and luminosity (Fossati et al. 1998) • Cooling model with external radiation for FSRQs (Ghisellini et al. 1998) • Selection/incompleteness biases (Giommi et al. 1999; Padovani et al. 2003, Padovani 2007) • Origin of the sequence • Galaxy evolution through reduction of fuel from surrounding gas and dust (Böttcher and Dermer 2002) • BZ effect (Cavaliere and d’Elia 2002) Foschini et al. 2009 arXiV 0908.3313 Where do RLNL Sy fit in? PMN J0948+0022 z=0.585 Abdo et al. 2009, ApJ, 699, 976 Dermer IAU 275 17 September 2010

  12. Fermi Study of the Blazar 3C 454.3 • 3C4 54.3: FSRQ at z = 0.859. • Spectral break ~ 2GeV, weak spectral variation… • Nov. 09 – Jan. 10 : the brightest gamma-ray source in the sky for over a week • April 10 : after slowly decaying, the flux brightened up again to 16×10-6 ph cm-2 s-1 Abdo et al. 2009 (3C 454.3) Dermer IAU 275 17 September 2010

  13. 3C 454.3 Light Curves see “Fermi Monitored Source List Light Curves” Dermer IAU 275 17 September 2010

  14. 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 Dermer IAU 275 17 September 2010

  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 profile (disk-wind) gg attenuation from H (13.6 eV) and He II (54.4 eV) recombination radiation deep within the BLR (Poutanen & Stern 2010) Consistency of synchrotron and Compton-scattered radiation spectrum with external photon field? Finke and Dermer (2010) Dermer IAU 275 17 September 2010

  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 (cf. Georganopoulos et al. 2001) Dermer IAU 275 17 September 2010

  17. PKS 2155-304 • X-ray selected BL Lac • z = 0.116, dL = 540 Mpc • Detected by EGRET, AGILE • August 2006: bright flares, detected by • Swift (Foschini et al. 2007) (3 ks/day) • HESS (Aharonian et al. 2007) • Variability timescale: ~5 minutes • BeppoSAX observed variability ~ 1 hr (Zhang et al. 2002) Dermer IAU 275 17 September 2010

  18. Demonstrations of Relativistic Outflows in Blazars • Compton catastrophe • Superluminal motion • gg opacity argument R < ctvar Assuming stationary emission region Dermer IAU 275 17 September 2010

  19. gg opacity and Gmin for PKS 2155-304 Lower EBL • Radio galaxy core emission well fit by sync./SSC model with d  G  few • The d-unification problem -- Decelerating Jet Model (Georganopoulos & Kazanas 2003) -- Spine and Sheath Model (Ghisellini et al. 2005) -- Colliding Shell Model Standard one-zone synchrotron/SSC model (g′min = 100 ) Doppler factor d >> 100 during flaring episodes Dermer IAU 275 17 September 2010

  20. g rays INTERNAL SHOCK Temporal Variability >RS G2 G1 • Colliding Shell Solution: • Variability • Unification • Light curves • UHECR acceleration RS >RS Size scale in stationary frame: DR > RS Size scale in comoving frame: DR = GDR > GRS (Lorentz contracted to size R in stationary frame) tvar > DR/c > GRS/c tvar = tvar /G RS/c Can small-opening angle colliding shells avoid this problem? Dermer IAU 275 17 September 2010

  21. e+ g e- • Magnetic obscuration of charged particle trajectories: • UHECR ions; Lepton secondaries ofgge+e- • Attenuation by the EBL: what happens to the generated pairs? • Pair halos(Aharonian, Coppi, & Völk 1994) • Temporal delay and Intergalactic Magnetic Field (IGMF) (Plaga 1995) • Temporal delay/echoes from bursting sources (Razzaque et al. 2004; Murase et al. 2008) • Angular extent of halos around blazars (Elyiv et al. 2009, Aharonian et al. 2009) • Halo extent at GeV energies  measurement of IGMF • SpectralTeV/GeV constraints on IGMF (d’Avezac et al. 2007; Neronov & Vovk 2010; Tavecchio et al. 2010) Nondetection by Fermi of TeV blazar sources  BIGMF >~ 10-16 G Extragalactic Background Light, Cascade Halo Emission, and the Intergalactic Magnetic Field Ando & Kusenko (2010; 1005.1924): ~30 halos in stacked data of 170 hard-spectrum Fermi blazars  BIGMF~10-15 G (lcoh/kpc)-1/2Criticisms: arXiv:1006.0164, Fermi statement Dermer IAU 275 17 September 2010

  22. Astrophysics of Compton Cascade Mean-free path for gg absorption strongly dependent on EBL Lepton g ~ e/2, deflection by q ~ g Energy loss dominated by Compton scattering off CMBR; Photons scattered to GeV energies Fermi IACTs 100 GeV 10 TeV

  23. Spectral Model of Halo Emission Cooling spectrum nFn n1/2 Compton-scattered spectrum nFn n3/2 Isotropized spectrum nFn n1/2 Tavecchio et al. (2010a,b) z =0.14 1ES 0229+200

  24. Limits on IGMF and Correlation Length Origin of the Intergalactic Magnetic Field (BIGMF): Primordial Early universe physics Biermann battery (~10-18 G) Galaxy dynamo other Recombination inflation Electroweak IES 0229+200 QCD IES 0347-121 Neronov & Vovk (2010)

  25. EBL Model _ _ _ _ _ _ EBL from stars and dust: Model C Finke et al. (2010) Good approximation below 15 TeV (e6 30 )

  26. Model vs. Data for Different Upper TeV energies Spectral “shoulder” at ~1 GeV

  27. Sensitivity of Halo Spectrum to EBL Model

  28. Ultra-High Energy Cosmic Ray Acceleration by Blazars through Fermi processes Proper frame (´) energy density of relativistic wind with apparent luminosity L Maximum particle energy R G Lorentz contraction: Dermer IAU 275 17 September 2010

  29. L - G diagram • Bulk Lorentz factor G from gg opacity arguments • Sources with jet Lorentz factor G must have jet power L exceeding heavy solid and dot-dashed curves to accelerate p and Fe respectively, to E = 1020 eV. • Upper limits to L vs. G defined by competition between synchrotron losses and acceleration time (dashed lines), and synchrotron losses and available time (dotted lines). Dermer IAU 275 17 September 2010

  30. Luminosity Density of g-ray Galaxies from Fermi Data • Need adequate luminosity density and number of sources within GZK radius • Need adequate luminosity • Fermi data favors high-Z ion acceleration by BL Lacs/FR1 radio galaxies • 1LAC AGNs • FSRQs • BL Lac • Misaligned Radio Galaxies • Starburst (and Star-forming) Swift+BATSE GRBs BATSE GRBs Dermer & Razzaque (2010) Dermer IAU 275 17 September 2010

  31. Summary • Great new spectral, temporal, Fermi LAT GeV database • Fermi provides uniform all-sky survey • though incomplete and TS- (not flux-) limited • Use to test black-hole demographics (if BZ from large “a” black holes, should mirror formation processes): relation of FSRQs and BL Lac objects • Is the blazar sequence an important clue or a selection bias? • ditto for the blazar divide… • Why spectral break between 1 – 10 GeV in FSRQs, LSPs, ISPs? • environment, electron energy distribution, radiation effects • Variability time in PKS 2155-304 << RS/c. • Solution in terms of colliding shell scenario • Misaligned Fermi AGNs violate “simplistic” unification • Solution in terms of colliding shell scenario • Measurement of IGMF through GeV—TeV observations • Fermi observations favor FR1/BL Lac over FRSQ and GRBs as sources of UHECRs Dermer IAU 275 17 September 2010

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