1. Gamma-ray Astronomy of XXI Century 100 MeV – 10 TeV

2. 1 keV1MeV1 GeV1 TeV FocusingCoded mask Compton telescopes  -conversion + calorimeter EGRET, Fermi Cherenkov telescopes Collimators

3. Objects visible in gamma-rays: -GRBs -Blazars & AGNs -Gamma-ray pulsars -Supernova remnants -Diffuse background

4. 1991 – 2000 «Compton, EGRET» 30 MeV – 100 GeV 2008 Fermi 20 MeV – 300 GeV 2000 - Cherenkov telescopes 20 GeV - 50 TeV

5. Batse GRBs

6. Fermi

7. Pass 7 vs. Pass 6 Pass 6 Pass 7 The break is very close to the He II absorption threshold! Pass 6 front/back

9. Gamma-ray bursts

10. Coincidence time + location 50 s 2o2o Express search for transients in Fermi data

11. 3-x coincidence Near-polar horizon

13. Vela pulsar Geminga 3C454 GRB Fall 2009 (4 of 12 GRBs) Now ~100

14. Short ~1.5 s Time, s

15. > 30 GeV

19. Quasars Cyg A 3C 273 M 87

21. E > 1 GeV

22. E > 100 MeV

24. 3C454.3

27.  –  -> e + e - He II Ly  edge 53 eV

28. Stern & Poutanen Photon-photon absorption breaks in Fermi spectra of bright blazars  GeV +  UV  e+ e- Poutanen & Stern 2010 Stern & Poutanen 2011 Stern & Poutanen 2014 Jet Broad line region

30. Pass6 Stacking analisys Stern & Poutanen 2012 Fortunately unpublished

31. medium ionization  = 1.5 medium ionization High ionization  = 2.5 high ionization  –  absorption He II Ly  and H Ly 

32. 44 66

33. Broad line region~ 10 3 R g Infrared dust radiation~ 10 5 R g CMB 10 8 R g Where the GeV radiation comes from? Looks like from ~ 10 3 RG  ~ sqrt(R/Rc) The jet launch is from the BH (Blandford-Znajek) Disk launch implies >10 4 RG

34. Emission mechanism is still unknown 1.Fermi acceleration in the jet due to internal perturbation (internal shocks, turbulence) + external Compton + some synchrotron Don’t speak about synchrotron – self Compton!!! 1.Photon breeding Stern & Poutanen 2006 – 2008 High energy photons produce a viscous friction between the jet and the external environment (works at  > 20 and a “strong” external environment) The jet is decelerated down to G ~ 15 independently of initial G

35. FSRQs (broad emission lines, softer spectra, softer low energy hump, very powerful) Versus BL Lacs (no broad emission lines, harder spectra, harder low energy hump, less powerful)

36. BL Lacs z ~ 0.05 – 0.4

37. Гамма-пульсары

38. Gamma-pulsars

39. Absorbed spectra of gamma-pulsars E a ~ 1 – 5 GeV

40. Fermi Yield Blazars 1100 (650 – BL-Lacs + 450 – FSRQs) AGNs 680 Gamma-ray pulsars 137 +29 Unidentified 1000

41. Diffuse emission from dark regions of the sky (0.25) Galactic plane  o production? The diffuse background

44. Galactic center 4 o Here people “observed” the dark matter annihilation line

45. Cosmic rays + gamma pulsars Galactic emission Galactic plane Galactic center

47. CTA ~ 0.4 km 2 (North) + 4 km 2 (South) H.E.S.S. II 10 5 m, energy threshold 20 GeV

48. MAGIC ~10 4 m 2 Threshold 25 GeV Mkn 421

49. VERITAS 10 5 m 2 50 GeV Arizona

50. 4100 kg Calorimeter 25 l r Gamma-400

51. Conclusions: 1.Gamma-ray astronomy becomes a precise science due to Fermi. 2.The uncertainties in calibration much exceed statistical errors 3.The main task for Cherenkov telescopes is the cross- calibration with Fermi and coordinated observations (IMHO) 4.The gap between X-rays and 100 Mev should be covered by any means 5.Open data are of crucial importance