Journal of Astronomy and Space Sciences

The Korean Space Science Society (한국우주과학회)
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Testing the Consistency of Unified Scheme of Seyfert Galaxies

  • Iyida, Evaristus U. (Astronomy and Astrophysics Research Group, Department of Physics and Astronomy, University of Nigeria) ;
  • Eya, Innocent O. (Astronomy and Astrophysics Research Group, Department of Physics and Astronomy, University of Nigeria) ;
  • Eze, Christian I. (Astronomy and Astrophysics Research Group, Department of Physics and Astronomy, University of Nigeria)
  • Received : 2022.02.04
  • Accepted : 2022.05.30
  • Published : 2022.06.15
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Abstract

The unified scheme of Seyfert galaxies hypothesizes that the observed differences between the two categories of Seyfert galaxies, type 1 (Sy1) and type 2 (Sy2) are merely due to the difference in the orientation of the toroidal shape of the obscuring material in the active galactic nuclei. We used in this paper, a sample consisting of 120 Seyfert galaxies at 1.40 × 109 Hz in radio, 2.52 × 1017 Hz in X-ray and 2.52 × 1023 Hz in γ-ray luminosities observed by the Fermi Large Area Telescope (Fermi-LAT) in order to test the unified scheme of radio-quiet Seyfert galaxies. Our main results are as follows: (i) We found that the distributions of multiwave luminosities (Lradio, LX-ray, and Lγ-ray) of Sy1 and Sy2 are completely overlapped with up to a factor of 4. The principal component analysis result reveals that Sy1 and Sy2 also occupy the same parameter spaces, which agrees with the notion that Sy1 and Sy2 are the same class objects. A Kolmogorov-Smirnov test performed on the sub-samples indicates that the null hypothesis (both are from the same population) cannot be rejected with chance probability p ~ 0 and separation distance K = 0.013. This result supports the fact that there is no statistical difference between the properties of Sy1 and Sy2 (ii) We found that the coefficient of the best-fit linear regression equation between the common properties of Sy1 and Sy2 is significant (r > 0.50) which plausibly implies that Sy1 and Sy2 are the same type of objects observed at different viewing angle.

Keywords

Acknowledgement

We sincerely thank anonymous referee for insightful comments and suggestions which helped to improve the manuscript.

References

  1. Abdo AA, Ackermann M, Ajello M, Atwood WB, Axelsson M, et al., Bright active galactic nuclei source list from the first three months of the Fermi large area telescope all-sky survey, Astrophys. J. 700, 597-622 (2009). https://doi.org/10.1088/0004-637X/700/1/597
  2. Ackermann M, Ajello M, Allafort A, Baldini L, Ballet J, et al., Search for gamma-ray emission from X-ray-selected Seyfert galaxies with Fermi-LAT, Astrophys. J. 747, 104-121 (2012). https://doi.org/10.1088/0004-637X/747/2/104
  3. Antonucci R, Unified models for active galactic nuclei and quasars, Annu. Rev. Astron. Astrophys. 31, 473-521 (1993). https://doi.org/10.1146/annurev.aa.31.090193.002353
  4. Antonucci RRJ, Miller JS, Spectropolarimetry and the nature of NGC 1068, Astrophys. J. 297, 621-632 (1985). https://doi.org/10.1086/163559
  5. Balokovic M, Smolcic V, Ivezic Z, Zamorani G, Schinnerer E, et al., Disclosing the radio loudness distribution dichotomy in quasars: an unbiased monte carlo approach applied to the SDSS-FIRST quasar sample, Astrophys. J. 759, 30 (2012). https://doi.org/10.1088/0004-637X/759/1/30
  6. Barthel PD, Is every quasar beamed?, Astrophys. J. 336, 606-611 (1989). https://doi.org/10.1086/167038
  7. Boroson T, Principal component analysis of QSO properties, vol. 311, AGN Physics with the Sloan Digital Sky Survey, Astronomical Society of the Pacific Conference Series, eds. Richards GT, Hall PB (Astronomical Society of the Pacific, 2004), 3.
  8. Boroson TA, Green RF, The emission-line properties of low-redshift quasi-stellar objects, Astrophys. J. Suppl. Ser. 80, 109 (1992). https://doi.org/10.1086/191661
  9. Cappi M, Panessa F, Bassani L, Dadina M, DiCocco G, et al., X-ray spectral survey with XMM-Newton of a complete sample of nearby Seyfert galaxies, A&A, 446, 459-470, (2006). https://doi.org/10.1051/0004-6361:20053893
  10. Curran SJ, Aalto S, Booth RS, Dense molecular gas in Seyfert galaxies, Astron. Astrophys. Suppl. Ser. 141, 193-209 (2000). https://doi.org/10.1051/aas:2000119
  11. Foschini L, What we talk about when we talk about blazars, Front. Astron. Space Sci. 4, 6 (2017). https://doi.org/10.3389/fspas.2017.00006
  12. Gallimore JF, Yzaguirre A, Jakoboski J, Stevenosky MJ, Axon DJ, et al., Infrared spectral energy distributions of seyfert galaxies: spitzer space telescope observations of the 12 ㎛ sample of active galaxies, Astrophys. J. Suppl. Ser. 187, 172 (2010). https://doi.org/10.1088/0067-0049/187/1/172
  13. Ghisellini G, Padovani P, Celotti A, Maraschi L, Relativistic bulk motion in active galactic nuclei, Astrophys. J. 407, 65 (1993). https://doi.org/10.1086/172493
  14. Heckman TM, Best PN, The coevolution of galaxies and supermassive black holes: insights from surveys of the contemporary universe, Annu. Rev. Astron. Astrophys. 52, 589-660 (2014). https://doi.org/10.1146/annurevastro-081913-035722
  15. Iyida EU, Eya IO, Odo FC, On the unified view of extragalactic sources based on their broadband emission properties, J. Astrophys. Astron. 42, 107 (2021). https://doi.org/10.1007/s12036-021-09778-4
  16. Iyida EU, Eze CI, Odo FC, On the evolution of Seyfert galaxies, BL Lacertae objects and flat-spectrum radio quasars, Astrophys. Space Sci. 367, 11 (2022). https://doi.org/10.1007/s10509-022-04042-9
  17. Iyida EU, Odo FC, Chukwude AE, Ubachukwu AA, Spectral properties of Fermi blazars and their unification schemes, Open Astron. 29, 168-178 (2020). https://doi.org/10.1515/astro-2020-0015
  18. Kellermann KI, Sramek R, Schmidt M, Shaffer DB, Green R, et al., VLA observations of objects in the Palomar Bright Quasar Survey, Astron. J. 98, 1195-1207 (1989). https://doi.org/10.1086/115207
  19. Kormendy J, Ho LC, Coevolution (or not) of supermassive black holes and host galaxies, Annu. Rev. Astron. Astrophys. 51, 511-653 (2013). https://doi.org/10.1146/annurevastro-082708-101811
  20. Maiolino R, Ruiz M, Rieke GH, Papadopoulos P, Molecular gas, morphology, and seyfert galaxy activity, Astrophys. J. 485, 552 (1997). https://doi.org/10.1086/304438
  21. Mas-Hesse JM, Rodriguez-Pascual PM, de Cordoba LS, Mirabel IF, Multiwavelength analysis of quasars, Seyfert galaxies, and starbursts, Astrophys. J. Supple. Ser. 92, 599-602, (1994). https://doi.org/10.1086/192022
  22. Moran EC, Barth AJ, Kay LE, Filippenko AV, The frequency of polarized broad emission lines in type 2 Seyfert galaxies, Astrophys. J. 540, L73 (2000). https://doi.org/10.1086/312876
  23. Odo FC, Ubachukwu AA, Chukwude AE, Relativistic beaming and orientation effects in BL Lacertae objects, J. Astrophys. Astron. 33, 279-290 (2012). https://doi.org/10.1007/s12036-012-9141-9
  24. Ojha V, Chand H, Krishna G, Intra-night optical variability of γ-ray detected narrow-line Seyfert1 galaxies, Mon. Not. R. Astron. Soc. 501, 4110-4122 (2021). https://doi.org/10.1093/mnras/staa3937
  25. Osterbrock DE, Seyfert galaxies with weak broad H alpha emission lines, Astrophys. J. 249, 462-470 (1981). https://doi.org/10.1086/159306
  26. Osterbrock DE, Pogge RW, The spectra of narrow-line Seyfert 1 galaxies, Astrophys. J. 297, 166-176 (1985). https://doi.org/10.1086/163513
  27. Padovani P, Alexander DM, Assef RJ, De Marco B, Giommi P, et al., Active galactic nuclei: what's in a name?, Astron. Astrophys. Rev. 25, 2 (2017). https://doi.org/10.1007/s00159-017-0102-9
  28. Pei Z, Fan J, Bastieri D, Yang J, Xiao H, Radio core dominance of Fermi/LAT-detected AGNs, Sci. China, Phys. Mech. Astron. 63, 259511 (2020). https://doi.org/10.1007/s11433-019-1454-6
  29. Press WH, Teukolsky SA, Vetterling WT, Flannery BP, Numerical Recipes in Fortran: The Art of Scientific Computing (Cambridge University Press, Cambridge, UK, 1994).
  30. Rakshit S, Stalin CS, Optical variability of narrow-line and broad-line Seyfert 1 galaxies, Astrophys. J. 842, 96 (2017). https://doi.org/10.3847/1538-4357/aa72f4
  31. Rowan-Robinson M, On the unity of activity in galaxies, Astrophys. J. 213, 635-647 (1977). https://doi.org/10.1086/155195
  32. Singal J, A determination of the gamma-ray flux and photon spectral index distributions of blazars from the Fermi-LAT 3LAC. Mon. Not. R. Astron. Soc. 454, 115-122 (2015). https://doi.org/10.1093/mnras/stv1964
  33. Singh V, Chand H, Investigating kpc-scale radio emission properties of narrow-line Seyfert 1 galaxies, Mon. Not. R. Astron. Soc. 480, 1796-1818 (2018). https://doi.org/10.1093/mnras/sty1818
  34. Urry CM, Padovani P, Unified schemes for radio-loud active galactic nuclei, Publ. Astron. Soc. Pac. 107, 803 (1995). https://doi.org/10.1086/133630
  35. Wolf J, Salvato M, Coffey D, Merloni A, Buchner J, et al., Exploring the diversity of Type 1 active galactic nuclei identified in SDSS-IV/SPIDERS, Mon. Not. R. Astron. Soc. 492, 3580-3601 (2020). https://doi.org/10.1093/mnras/staa018
  36. Xu C, Livio M, Baum S, Radio-loud and radio-quiet active galactic nuclei, Astron. J. 118, 1169-1176 (1999). https://doi.org/10.1086/301007
  37. Xu D, Komossa S, Zhou H, Lu H, Li C, et al., Correlation analysis of a large sample of narrow-line Seyfert 1 galaxies: linking central engine and host properties, Astron. J. 143, 83 (2012). https://doi.org/10.1088/0004-6256/143/4/83
  38. Yuan W, Zhou HY, Komossa S, Dong XB, Wang TG, et al., A population of radio-loud narrow-line Seyfert 1 galaxies with blazar-like properties? Astrophys. J. 685, 801 (2008). https://doi.org/10.1086/591046
  39. Zhang L, Fan J, Zhu J, Radio loudness and classification for radio sources, Publ. Astron. Soc. Jpn. 73, 313-325 (2021) https://doi.org/10.1093/pasj/psaa122