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Lorentz factor estimation for radio sources

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Abstract

In this paper, a sample including 68 blazars (18 BL Lacs and 50 FSRQs) with known Doppler factors and superluminal velocity from our previous papers is presented. Both the Lorentz factors (Γ) and viewing angles (θ) are estimated for the 68 sources. The relationship between BL Lacs and FSRQs is also revisited using the two variables of gG and θ. The Lorenz factors are in the range of 2.33 to 64.07. The viewing angles are in the range of 0.04 to 24.56. The averaged value of the viewing angle for BL Lacs is slightly larger than that for FSRQs, while the averaged value of the Lorentz factor for BL Lacs is smaller than that for FSRQs.

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References

  1. Aller M F, Aller H D, Hughes P A. Radio band observations of blazar variability. J Astrophys Astron, 2011, 32: 5–11

    Article  ADS  Google Scholar 

  2. Fan J H. Optical variability of blazars. Chin J Astron Astrophys, 2005, 5(Suppl): 213–223

    Article  ADS  Google Scholar 

  3. Fan J H. The basic parameters of γ-ray-loud blazars. Astron Astrophys, 2005, 436: 799–804

    Article  ADS  Google Scholar 

  4. Fan J H, Huang Y, Yuan Y H, et al. Brightness temperature for 166 radio sources. Res Astron Astrophys, 2009, 9: 751–760

    Article  ADS  Google Scholar 

  5. Fan J H, Liu Y, Li Y, et al. Variability of blazars. J Astrophys Astron, 2011, 32: 67–71

    Article  ADS  Google Scholar 

  6. Gupta A C. UV and X-ray variability of blazars. J Astrophys Astron, 2011, 32: 155–161

    Article  ADS  Google Scholar 

  7. Wang J M. Multiwavelength Variability of Blazars. Guangzhou: Guangzhou University, 2010. 22–24

    Google Scholar 

  8. Wu X B, Liu F K, Kong M Z, et al. Estimating black hole masses of blazars. J Astrophys Astron, 2011, 32: 209–215

    Article  ADS  Google Scholar 

  9. Xie G Z, Zhou S B, Li K H, et al. CCD photometric studies of rapid variability in eight blazars. Mon Not R Astron Soc, 2004, 348: 831–845

    Article  ADS  Google Scholar 

  10. Yang J H, Fan J H, Yang R S. The line emissions and polarization in blazars. Sci China-Phys Mech Astron, 2010, 53(6): 1162–1168

    Article  MathSciNet  ADS  Google Scholar 

  11. Yang J H, FAN J H. The central black hole masses for the γ-ray loud blazars. Sci China-Phys Mech Astron, 2010, 53(10): 1921–1927

    Article  ADS  Google Scholar 

  12. Zhang Y W, Fan J H. Statistics of superluminal motion in active galactic nuclei. Chin J Astron Astrophys, 2008, 8: 385–394

    Article  ADS  Google Scholar 

  13. Zhang H J, Zhao G, Zhang X, et al. Long-term optical spectra variability of BL Lacertae object S5 0716+714. J Astrophys Astron, 2011, 32: 131–135

    Article  ADS  Google Scholar 

  14. Fan J H, Yang J H, Pan J, et al. The relationship between radio core dominance parameter and spectral index in different classes of extragalactic radio source. Res Astron Astrophys, 2011, 11: 1413–1428

    Article  ADS  Google Scholar 

  15. Ghisellini G, Padovani P, Celotti A, et al. Relativistic bulk motion in active galactic nuclei. Astrophys J, 1993, 407: 65–82

    Article  ADS  Google Scholar 

  16. Urry C M, Padovani P, Stickel M. Fanaroff-Riley I galaxies as the parent populations of BL Lacertae objects. III—Radio constraints. Astrophys J, 1991, 382: 501–507

    Article  ADS  Google Scholar 

  17. Padovani P, Urry C M. Luminosity functions, relativistic beaming, and unified theories of high-luminosity radio sources. Astrophys J, 1992, 387: 449–457

    Article  ADS  Google Scholar 

  18. Jiang D R, Cao X W, Hong X Y. The inhomogeneous jet parameters in active galactic nuclei. Astrophys J, 1998, 494: 139–149

    Article  ADS  Google Scholar 

  19. Xie G Z, Zhang Y H, Fan J H, et al. The relation between BL Lacertae objects and OVV quasars, and the unified model of BL Lacertae objects, FR-I and FR-II (G) radio galaxies. Astron Astrophys, 1993, 278: 6–10

    ADS  Google Scholar 

  20. Fan J H, Okudaira A, Lin R G, et al. The unified scheme of BL Lac Objects and the k-band Hubble diagram. Astrophys Space Sci, 1997, 253: 275–284

    Article  ADS  Google Scholar 

  21. Owen F N, Ledlow M J, Keel W C. Optical spectroscopy of radio galaxies in Abell clusters II. BL d Lacs and FR I unification. Astron J, 1996, 111: 53–63

    Google Scholar 

  22. Paolo P, Megan U C. Fanaroff-Riley I galaxies as the parent population of BL Lacertae objects. II—Optical constraints. Astrophys J, 1991, 368: 373–379

    Article  ADS  Google Scholar 

  23. Xu Y D, Cao X W, Wu Q W. On the BL Lacertae objects/radio quasars and the FR I/II dichotomy. Astrophys J, 2009, 694: 107–110

    Article  ADS  Google Scholar 

  24. Yang R S, Yang J H, Wang Y X. Relationship among FR-I, FR-II(Q) and FR-II(G) Radio Galaxies. J Astrophys Astron, 2011, 32: 307–308

    Article  ADS  Google Scholar 

  25. Owen F N, Laing R A. CCD surface photometry of radio galaxies. I —FR class I and II sources. Mon Not R Astron Soc, 1989, 238: 357–378

    ADS  Google Scholar 

  26. Ishwara-Chandra C H, Saikia D J. Giant radio sources. Mon Not Roy Astron Soc, 1999, 309: 100–112

    Article  ADS  Google Scholar 

  27. Chiaberge M, Capetti A, Celotti A. The HST view of FR I radio galaxies: Evidence for non-thermal nuclear sources. Astron Astrophys, 1999, 349: 77–87

    ADS  Google Scholar 

  28. Ghisellini G, Celotti A. The dividing line between FR I and FR II radio-galaxies. Astron Astrophys, 2001, 379: 1–4

    Article  ADS  Google Scholar 

  29. Wu Q W, Cao X W. Jet power extracted from ADAF and the applications to X-Ray binaries and the radio galaxy FR dichotomy. Astrophys J, 2008, 687: 156–161

    Article  ADS  Google Scholar 

  30. Rawlings S, Saunders R. Evidence for a common central-engine mechanism in all extragalactic radio sources. Nature, 1991, 349: 138–140

    Article  ADS  Google Scholar 

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Authors and Affiliations

  1. Department of Physics and Electronics Science, Hunan University of Arts and Science, Changde, 415000, China

    JiangHe Yang

  2. Center for Astrophysics, Guangzhou University, Guangzhou, 510006, China

    JiangHe Yang & JunHui Fan

  3. Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province, Guangzhou, 510006, China

    JunHui Fan & YuHai Yuan

  4. Laboratory Center, Guangzhou University, Guangzhou, 510006, China

    YuHai Yuan

Authors
  1. JiangHe Yang
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  2. JunHui Fan
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  3. YuHai Yuan
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Correspondence to JiangHe Yang.

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Yang, J., Fan, J. & Yuan, Y. Lorentz factor estimation for radio sources. Sci. China Phys. Mech. Astron. 55, 1510–1514 (2012). https://doi.org/10.1007/s11433-011-4807-x

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  • DOI: https://doi.org/10.1007/s11433-011-4807-x

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