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Relativistic Beaming Effect for Fermi Blazars

The 4 th Fermi Asian Network(FAN4) Workshop July 8-12, 2013, HKU. Relativistic Beaming Effect for Fermi Blazars. Junhui Fan Co-workers: D. Bastirie, J.H. Yang, Y. Liu, D.X. Wu, S.H. Li, J.Y. Zhang. Welcome to. IAUS 313: Extragalactic Jets from every angle Sept, 13-21, 2014, Ecuador

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Relativistic Beaming Effect for Fermi Blazars

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  1. The 4th Fermi Asian Network(FAN4) Workshop July 8-12, 2013, HKU Relativistic Beaming Effect for Fermi Blazars Junhui Fan Co-workers: D. Bastirie, J.H. Yang, Y. Liu, D.X. Wu, S.H. Li, J.Y. Zhang FAN4,2013-07-08/12, HKU

  2. Welcome to IAUS 313: Extragalactic Jets from every angle Sept, 13-21, 2014, Ecuador 1st announcement will be available in Sept. , 2013 FAN4,2013-07-08/12, HKU

  3. Welcome to IAUS 313: Extragalactic Jets from every angle September 2014, Ecuador Scientific Organizing Committee (SOC) FAN4,2013-07-08/12, HKU

  4. Outline • Introduction • Beaming effect for Fermi Blazars • Summary FAN4,2013-07-08/12, HKU

  5. 1. Introduction FAN4,2013-07-08/12, HKU

  6. INTRODUCTION Observations show that some sources with particular observational properties RBLs LBLs 1) BL Lacertae objects--BLs, XBLs HBLs 2) Flat Spectrum Radio Quasars—FSRQs FAN4,2013-07-08/12, HKU

  7. What is a BL Lac Object? Strittmatter et al. (1972) suggested that objects similar to BL Lac comprise a class—BL Lacertae objects. • Absence of emission lines in the core sources; weak emission lines were found in BLs (Miller et al. 1978) • Rapid variability at radio, infrared, and visual wavelength bands • Nonthermal continuum with most of the luminosity radiated at infrared wavelength • Strong and rapidly varying polarization. Stein et al. 1976, ARA&A, 14 FAN4,2013-07-08/12, HKU

  8. What is an FSRQ? Optically violently variable quasars--OVVs, (m>1.0m) ( Penston & Cannon,1970) Kinman (1975) OVVs tend to have steep optical spectra and be associated with compact variable radio sources which have flat radio spectra at GHz frequencies. Highly polarized quasars--HPQs ( p>3.0%), (Moore and Stockman 1981, ApJ, 243 ) , 45% Core-dominated quasars--CDQs ( R = Lc/Le > 1.0) ….SM FAN4,2013-07-08/12, HKU

  9. Objects with one of the above properties INTRODUCTION BLAZARS BLAZARS (BL Lacs and FSRQs) extragalactic objects with rapid variability, high luminosity, high and variable polarization, or superluminal motions. The term “blazar” was coined, half in jest, by Ed Speigel at the first conference on BL lac objects in Pittsburg. Fan et al. 2013, RAA, Fan et al. 2013, IAUS 290 Strong gamma-ray emissions FAN4,2013-07-08/12, HKU

  10. INTRODUCTION INTRODUCTION BLAZARS BLAZARS (BL Lacs and FSRQs) Special subclass of AGNs: extragalactic objects with rapid variability, high luminosity, high and variable polarization, have/no strong emission lines, gamma-ray emissions, or superluminal motions. FAN4,2013-07-08/12, HKU

  11. Sequence of Blazars FAN4,2013-07-08/12, HKU

  12. 窄线区 AGN Model 宽线区 喷流 黑洞 吸积盘 Doppler Factor Jet Mechanism, Mass Doppler Evol. Collimation FAN4,2013-07-08/12, HKU Standard Model for AGNs

  13. Radio Doppler Factor Determination FAN4,2013-07-08/12, HKU

  14. EGRET & Fermi/LAT FAN4,2013-07-08/12, HKU

  15. Gamma-Ray Emissions from Blazars Some Statistical Results in Beaming effect for gamma-ray loud Blazars EGRET FERMI FAN4,2013-07-08/12, HKU

  16. EGRET EGRET (Energetic Gamma Ray Experiment Telescope) onboard the satellite COMPTON-GRO(Gamma Ray Observatory) EGRET located in orbit around Earth from April 1991 to June 2000. This observatory was equipped with different instruments, capable to detect high-energy emission, namely gamma-rays, coming from space. The EGRET instrument, which was sensible at energies between 20 MeV and 30 GeV. FAN4,2013-07-08/12, HKU

  17. EGRET FAN4,2013-07-08/12, HKU

  18. Huang, L.H., Jiang, D.R., Cao, X.W.,1999, A&A, 341, 74-80 EGRET Radio Doppler Factor FAN4,2013-07-08/12, HKU

  19. MW Correlations From EGRET SourcesCheng K.S. Zhang, X. Zhang, Li. 2000, ApJ EGRET FAN4,2013-07-08/12, HKU

  20. Fan et al. 2009, PASJ EGRET Beaming Model FAN4,2013-07-08/12, HKU

  21. Gamma-Radio From EGRETFan et al. 1998, A&A EGRET FAN4,2013-07-08/12, HKU

  22. Simple Results from EGRET EGRET-Blazars show 1、The ratio of gamma to optical flux densities increases with Doppler factor (Huang, L.H., Jiang, D.R., Cao, X.W., 1999, A&A, 341, 74-80) 2、Gamma emissions are associated with the Doppler factor (Fan et al. 2009, PASJ) 3、Gamma emissions are correlated with radio emissions. (Cheng K.S. et al. 2000, ApJ) FAN4,2013-07-08/12, HKU

  23. Fermi/LAT FAN4,2013-07-08/12, HKU

  24. AGNs: Fermi View(11 months) Abdo et al. 2010, ApJS188, 405 For the 1451 detected sources, 600 are unidentified, 851 have associated objects, out of them about 700 Blazars. Used the position association with ROSAT, identified 30 sources, out of them 18 are blazars, 7 are AGNs, binary/SNR/star 1/each, ? 2. FAN4,2013-07-08/12, HKU

  25. AGNs: Fermi View(11 months) Abdo et al. 2010, ApJS188, 405 FAN4,2013-07-08/12, HKU

  26. The 2nd Catalog of AGNs (Fermi 2 years)Ackermann, M. et al. 2011, ArXiv:1108.1422 1017 gamma-ray sources located at high Galactic latitude (|b|>10). 886 AGNs: 705 Blazars 395 BL Lacs 310 FSRQs 157 Blazar candidates 8 misaligned AGNs 4 NLS1 10 AGNs of other types 2 Starburst galaxies FAN4,2013-07-08/12, HKU

  27. Red: FSRQs, Blue: BL Lacs, Magenta: non-blazar AGNs, Green: AGNs of unknown type. Ackermann, M. et al. 2011, ArXiv:1108.1422 FAN4,2013-07-08/12, HKU

  28. Fermi 36 monthsRefer to Pablo Saz Parkinson this workshop FAN4,2013-07-08/12, HKU

  29. Beaming Effect in Fermi Blazars 1. Variability Index 2. Brightness Temperature 3. Doppler factor and viewing angle 4. Radio polarization FAN4,2013-07-08/12, HKU

  30. Variability IndexRefer to Pablo Saz Parkinson this workshop FAN4,2013-07-08/12, HKU

  31. Radio Variability KOVALEV et al. 2009, ApJL Activity index in radio band: V=(S2008-S1999-2007)/S1999-2008 Statistical conclusion: MOJAVE-FERMI AGN are in a high activity state, both in total intensity, and polarization ‘ELBS’—Extragalactic LAT Bright Source sample. FERMI FAN4,2013-07-08/12, HKU

  32. Brightness Temperature KOVALEV et al. 2009, ApJL At a 99.9 per cent confidence, that the median Tb values for FERMI-detected sources are statistically higher than those for the rest of the sample. FERMI FAN4,2013-07-08/12, HKU

  33. Beaming in LAT SourcesSavolainen et al. 2010, A&A,512 Savolainen considered 62 with apparent velocity from MOJAVE and Doppler factors from radio variability from Metsahovi Radio Observatory. Then compare the source detected by LAT and those not-detected. FERMI FAN4,2013-07-08/12, HKU

  34. Beaming in LAT SourcesSavolainen et al. 2010, A&A,512 Savolainen considered 62 with apparent velocity from MOJAVE and Doppler factors from radio variability from Metsahovi Radio Observatory. Then compare the source detected by LAT and those not-detected. They found • The FERMI-detected blazars have on average higher Doppler factors than non-FERMI-detected blazars 2. Most interestingly, γ-ray bright blazars have a distribution of comoving frame viewing angles that is significantly narrower than that of γ-ray weak blazars. FERMI FAN4,2013-07-08/12, HKU

  35. Radio Polarization in Fermi SourcesHovatta et al. 2010, IJMPD 2002-2008 3 months Post-2008 FERMI FAN4,2013-07-08/12, HKU

  36. Radio Polarization in Fermi SourcesHovatta et al. 2010, IJMPD They found that the polarization in the FERMI detected era is higher for the investigated sources. In factor, we have also obtained that the polarization is associated with the Doppler factor (Fan, Cheng, Zhang, 1997, A&A) . Gamma-ray emissions are associated with beaming. FERMI FAN4,2013-07-08/12, HKU

  37. Polarization & Beaming effect Fan, Cheng, Zhang, 1997, A&AFan, 2002, PASJ FAN4,2013-07-08/12, HKU

  38. Simple Results Fermi-Blazars show 1、Strong radio activity 2、Higher brightness temperature 3、Higher Doppler factors， narrower viewing angle 4、Higher radio polarization Beaming effect FAN4,2013-07-08/12, HKU

  39. 2. Beaming effects for Fermi Blazars • Gamma-Ray luminosity vs. Radio Doppler Factor • Gamma-Ray luminosity vs.Apparent Velocity • Gamma-Ray Luminosity vs.Core-dominance parameter • Determining the Gamma-ray Doppler Factor FAN4,2013-07-08/12, HKU

  40. Massaro, Giommi, Leto, et al 2012 BZCAT 1FGL 2FGL FAN4,2013-07-08/12, HKU

  41. i. 0.8 Fan et al. 2013, PASJ 66 Sources 1FGL Catalogue Fan et al. 2010 Ghisellini et al. 1993 Huang, Jiang, Cao, 1999 Lahteenimaki & Valtaoja, 1999 FAN4,2013-07-08/12, HKU

  42. ii. FAN4,2013-07-08/12, HKU

  43. iii Core-Dominance Parameter FAN4,2013-07-08/12, HKU

  44. iii FAN4,2013-07-08/12, HKU

  45. iii FSRQ 113 Fermi Blazars BL FAN4,2013-07-08/12, HKU

  46. FAN4,2013-07-08/12, HKU

  47. Log (1+R) FAN4,2013-07-08/12, HKU

  48. iv. To determine the Doppler Factors FAN4,2013-07-08/12, HKU

  49. Consideration The strong γ-rays are detected for so many blazars implying that the beaming effect is presented in the γ -ray emissions, otherwise, the γ-rays should have been absorbed due to pair-production on collision with the lower energetic photons. Mattox, et al(1993). considered the pair-production optical depth, they assumed that (1) the X-ray is produced in the same region as the γ-rays, and that a similar X-ray intensity was extant at the time of the γ-ray observation, (2) the emission region is spherical, (3) the emission is isotropic, and the size of the emission region is constrained by time variation to be less than R = c ΔT/(1+z), there Δ T is the timescale of variability, c is the speed of light, z is the redshift. Finally, they obtained the optical depth, FAN4,2013-07-08/12, HKU

  50. Optical Depth When the beaming is presented in the emission, then the optical depth can be expressed in the following form δ:Doppler factor FkeV: X-ray flux density α: X-ray spectral index Eγ: γ-ray energy (GeV) ΔT: Variability time scale dL: Luminosity distance (Mpc) FAN4,2013-07-08/12, HKU

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