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The Fermi blazars divide

The Fermi blazars divide. Gabriele Ghisellini Osservatorio Astronomico di Brera In collaboration with L. Maraschi and F. Tavecchio. Bright Fermi blazars. >100 with >10 s detection 57 FSRQs and 42 BL Lacs Redshift for all FSRQs and for 30 BL Lacs. FSRQs. TeV.

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The Fermi blazars divide

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  1. The Fermi blazars divide Gabriele Ghisellini Osservatorio Astronomico di Brera In collaboration with L. Maraschi and F. Tavecchio

  2. Bright Fermi blazars • >100 with >10s detection • 57 FSRQs and 42 BL Lacs • Redshift for all FSRQs and for 30 BL Lacs

  3. FSRQs TeV g-ray energy spectral index ag There is a sequence… Ghisellini, Maraschi, Tavecchio 2009 BL Lacs

  4. …despite dramatic variability Ghisellini, Maraschi, Tavecchio 2009

  5. BL Lac

  6. Fermi

  7. 454.3

  8. Agile Fermi

  9. 0528

  10. Fermi

  11. 279

  12. MAGIC Fermi

  13. The“blazarsequence” FSRQs Steep Lg Fossati et al. 1998; Donato et al. 2001 BL Lacs Flat

  14. Steep FSRQs Flat BL Lacs

  15. The divide

  16. The blazar divide

  17. ~100

  18. Pjet~Maccrc2 Ldisk > ~ ~100

  19. Celotti & GG 2008

  20. Celotti & GG 2008, Maraschi+ 2008

  21. GG, Tavecchio & Ghirlanda in prep, Celotti & GG 2008, Maraschi+ 2008

  22. Pjet~Maccrc2 Ldisk > ~ Ldisk~MEddc2 Ldisk~0.01MEddc2 ~100

  23. Ledlow & Owen Ghisellini & Celotti 2000

  24. Ledlow & Owen Ghisellini & Celotti 2000

  25. Jet power vs disk Lum. BL Lacs, FSRQ FRI, FRII Photon trapping Pjet LdiskPjet e-p decoupling Ldisk ~10-2 Disk accretion rate (Eddington units)

  26. M>0.01MEdd External Compton strong cooling 1/2 1/2 RBLR ~ Ldisk  UBLR= const RTorus~ Ldisk  UIR= const MeV Far IR Torus ~1-10 pc BLR Standard disk

  27. M<0.01MEdd SSC only weak cooling 1/2 RBLR ~ Lioniz  ~No BLR (or very small) TeV X TeV BLR <<0.2 pc “ADAF disk”

  28. Evolution? (e.g. Cavaliere & D’Elia 2002) • M should increase with redshift • In the past more FSRQs (and FRII): positive evolution? • Now more BL Lacs (and FRI): negative evolution? • And taken together…? Similar to radio-quiet or not?

  29. Conclusions/Predictions • The most powerful Fermi blazars should be accreting near Eddington, and have the largest black hole masses • Also radio-quiet should have much weaker broad lines for M<0.01MEdd • As the survey goes on, including weaker sources….

  30. smaller M 0948 ~forbidden except extraordinary and rare states

  31. Conclusions/Predictions • The most powerful Fermi blazars should be accreting near Eddington, and have the largest black hole masses • Also radio-quiet should have much weaker broad lines for M<0.01MEdd

  32. From Ho, 2008, ARAA.. For radio-quiet: “8. Low luminosity AGNs are not simply scaled-down versions of powerful AGNs. Their central engines undergo fundamental changes when the accretion rate << Eddington. In this regime, the BLR and obscuring torus disappear… 9. Below L~0.01% Eddington, the canonical accretion disk transforms into an inner vertically thick and radiatively inefficient accretion flow….”

  33. M Ljet propto Ldisk M2 1/2 Ljet propto Ldisk ADAF (Narayan et al.)

  34. By modeling, we find physical parameters in the comoving frame. gpeak is the energy of electrons emitting at the peak of the SED EGRET blazars

  35. Low power slow cooling large gpeak Big power fast cooling small gpeak

  36. tcool 1/(gpeak U) = R/c µ 2 ggpeakU = const µ

  37. Power of jets

  38. The power of blazar jets G Lr = radiation Le = relat. electrons Lp = protons LB = B-field R ~1017 cm

  39. High power If one p per e- Relat. electrons Celotti & Ghisellini 2007 Powerful jets are not magnetically dominated Magnetic Field Radiation

  40. Low power If one p per e- Relat. electrons Celotti & Ghisellini 2007 Magnetic Field Radiation

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