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On the Extent of the Existence of Broad Line Region in Seyfert Galaxies

Received: 29 July 2019     Accepted: 21 September 2019     Published: 9 October 2019
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Abstract

We present statistical results from a very large sample of Seyfert galaxies (217,272 galaxies) obtained from SDSS DR10 (Sloan Digital Sky Survey Data Release 10). From their observed parameters which includes; flux of hydrogen alpha (Hα), luminosity distance and velocity dispersion, we computed other relevant parameters such as; bolometric luminosity, black hole mass and mass accretion rate, which enabled us classify these Seyfert galaxies into Seyfert 1s (188,486 galaxies) and Seyfert 2s (28,786 galaxies). Analyses on these computed parameters revealed that Seyfert 2 galaxies were less luminous, more massive and accrete less matter than the Seyfert 1 galaxies. Further analysis on Seyfert 2s based on their mass accretion rate led to their classification into hidden broad line region (HBLR) Seyfert 2s (12,988 galaxies) and non-hidden broad line region (non-HBLR) Seyfert 2s (15,798 galaxies) which shows that, the HBLR S2s accrete more matter than the non-HBLR S2s. All the results obtained suggest that the bolometric luminosity alone is not sufficient in determining the extent of the existence of the BLR in Seyfert 2 galaxies rather the mass accretion rate should be taking into consideration in determining the appearance and disappearance of the BLR.

Published in American Journal of Astronomy and Astrophysics (Volume 7, Issue 2)
DOI 10.11648/j.ajaa.20190702.12
Page(s) 33-38
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2019. Published by Science Publishing Group

Keywords

Galaxies, Seyfert, Accretion Rate, Bolometric Luminosity and Broad Line Region

References
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[8] Goad, M. R., Korista, K. T., and Ruff, A. J. (2012). The Broad Emission Line Region: The Confluence of the Outer Accretion Disc with the Inner Edge of the Dusty Torus. MNRAS, 426 (4), 3086-3111.
[9] Ricci, C., Walter, R., Courvoisier, T. J.-L., and Paltani, S. (2011). Reflection in Seyfert Galaxies and the Unified Model of AGN. A & A, 532, A102.
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  • APA Style

    Oyor David Ifeanyichukwu, Ogwo Jemima Ngozi. (2019). On the Extent of the Existence of Broad Line Region in Seyfert Galaxies. American Journal of Astronomy and Astrophysics, 7(2), 33-38. https://doi.org/10.11648/j.ajaa.20190702.12

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    ACS Style

    Oyor David Ifeanyichukwu; Ogwo Jemima Ngozi. On the Extent of the Existence of Broad Line Region in Seyfert Galaxies. Am. J. Astron. Astrophys. 2019, 7(2), 33-38. doi: 10.11648/j.ajaa.20190702.12

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    AMA Style

    Oyor David Ifeanyichukwu, Ogwo Jemima Ngozi. On the Extent of the Existence of Broad Line Region in Seyfert Galaxies. Am J Astron Astrophys. 2019;7(2):33-38. doi: 10.11648/j.ajaa.20190702.12

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  • @article{10.11648/j.ajaa.20190702.12,
      author = {Oyor David Ifeanyichukwu and Ogwo Jemima Ngozi},
      title = {On the Extent of the Existence of Broad Line Region in Seyfert Galaxies},
      journal = {American Journal of Astronomy and Astrophysics},
      volume = {7},
      number = {2},
      pages = {33-38},
      doi = {10.11648/j.ajaa.20190702.12},
      url = {https://doi.org/10.11648/j.ajaa.20190702.12},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajaa.20190702.12},
      abstract = {We present statistical results from a very large sample of Seyfert galaxies (217,272 galaxies) obtained from SDSS DR10 (Sloan Digital Sky Survey Data Release 10). From their observed parameters which includes; flux of hydrogen alpha (Hα), luminosity distance and velocity dispersion, we computed other relevant parameters such as; bolometric luminosity, black hole mass and mass accretion rate, which enabled us classify these Seyfert galaxies into Seyfert 1s (188,486 galaxies) and Seyfert 2s (28,786 galaxies). Analyses on these computed parameters revealed that Seyfert 2 galaxies were less luminous, more massive and accrete less matter than the Seyfert 1 galaxies. Further analysis on Seyfert 2s based on their mass accretion rate led to their classification into hidden broad line region (HBLR) Seyfert 2s (12,988 galaxies) and non-hidden broad line region (non-HBLR) Seyfert 2s (15,798 galaxies) which shows that, the HBLR S2s accrete more matter than the non-HBLR S2s. All the results obtained suggest that the bolometric luminosity alone is not sufficient in determining the extent of the existence of the BLR in Seyfert 2 galaxies rather the mass accretion rate should be taking into consideration in determining the appearance and disappearance of the BLR.},
     year = {2019}
    }
    

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  • TY  - JOUR
    T1  - On the Extent of the Existence of Broad Line Region in Seyfert Galaxies
    AU  - Oyor David Ifeanyichukwu
    AU  - Ogwo Jemima Ngozi
    Y1  - 2019/10/09
    PY  - 2019
    N1  - https://doi.org/10.11648/j.ajaa.20190702.12
    DO  - 10.11648/j.ajaa.20190702.12
    T2  - American Journal of Astronomy and Astrophysics
    JF  - American Journal of Astronomy and Astrophysics
    JO  - American Journal of Astronomy and Astrophysics
    SP  - 33
    EP  - 38
    PB  - Science Publishing Group
    SN  - 2376-4686
    UR  - https://doi.org/10.11648/j.ajaa.20190702.12
    AB  - We present statistical results from a very large sample of Seyfert galaxies (217,272 galaxies) obtained from SDSS DR10 (Sloan Digital Sky Survey Data Release 10). From their observed parameters which includes; flux of hydrogen alpha (Hα), luminosity distance and velocity dispersion, we computed other relevant parameters such as; bolometric luminosity, black hole mass and mass accretion rate, which enabled us classify these Seyfert galaxies into Seyfert 1s (188,486 galaxies) and Seyfert 2s (28,786 galaxies). Analyses on these computed parameters revealed that Seyfert 2 galaxies were less luminous, more massive and accrete less matter than the Seyfert 1 galaxies. Further analysis on Seyfert 2s based on their mass accretion rate led to their classification into hidden broad line region (HBLR) Seyfert 2s (12,988 galaxies) and non-hidden broad line region (non-HBLR) Seyfert 2s (15,798 galaxies) which shows that, the HBLR S2s accrete more matter than the non-HBLR S2s. All the results obtained suggest that the bolometric luminosity alone is not sufficient in determining the extent of the existence of the BLR in Seyfert 2 galaxies rather the mass accretion rate should be taking into consideration in determining the appearance and disappearance of the BLR.
    VL  - 7
    IS  - 2
    ER  - 

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Author Information
  • Department of Science Laboratory Technology, Akanu Ibiam Federal Polytechnic, Afikpo, Nigeria

  • Department of Physics, Abia State University, Uturu, Nigeria

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