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

Oyor David Ifeanyichukwu; Ogwo Jemima Ngozi

doi:doi:10.11648/j.ajaa.20190702.12

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

Oyor David Ifeanyichukwu, Ogwo Jemima Ngozi

Published in American Journal of Astronomy and Astrophysics (Volume 7, Issue 2)

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

[1]	Singh, V., Shastri, P., Risaliti G. (2011). Measuring the Level of Nuclear Activity in Seyfert Galaxies and the Unification Scheme. A & A, 532, A84.
[2]	Schmidt, M. and Green, R. F. (1983). Quasar Evolution derived from the Palomar Bright Quasar Survey and other Complete Quasar Surveys. ApJ, 269, 352.
[3]	Peterson, B. M. (1997). An Introduction to Active Galactic Nuclei. Cambridge University Press.
[4]	Maiolino, R. and Rieke, G. H. (1995). Low-Luminosity and Obscured Seyfert Nuclei in Nearby Galaxies. ApJ, 454; 95-105.
[5]	Petrov, G. T. (2004) (ed). Active Galaxy Nuclei. Bulgarian Academy of Science/Institute of Astronomy.
[6]	Davidsen, A. F. (1993). Far-ultraviolet Astronomy on the Astro-1 Space Shuttle Mission. Science, 259 (5093), 327-334.
[7]	Ridpath, I. (1997). Dictionary of Astronomy. Oxford University Press. United Kingdom.
[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.
[10]	Antonucci, R. R. J. and Miller, J. S. (1985). Spectropolarimetry and the Nature of NGC 1068. ApJ, 297, 621-632.
[11]	Antonucci, R. R. J. (1993). Unified Models for Active Galactic Nuclei and Quasars. ARA & A, 31, 473.
[12]	Singh, V., Shastri, P., Ishwara-Chandra, C. H., and Athreya, R. (2013). Low Frequency Radio Observations of Seyfert Galaxies: A Test of the Unification Scheme. A & A, 554, A85.
[13]	Ahn, C. P., Alexandroff, R., Allende, Prieto C., et. al., (2013). The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment. ApJ, arXiv: 1307.7735.
[14]	Elitzur, M., Ho, L. C., and Trump, J. R. (2014). Evolution of Broad-Line Emission from Active Galactic Nuclei. MNRAS, 438, 3340-3351.
[15]	Laor, A. (2003). On the Nature of Low Luminosity Narrow Line AGN. ApJ, 590, 86.
[16]	Pappa, A., Georgantopoulos, I., Stewart G. C., and Zezas, A. L. (2001). The X-ray Spectra of Optically Selected Seyfert 2 galaxies: Are there any Sy2 Galaxies with no Absorption? MNRAS, arXiv: astro-ph/0104061.

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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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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

Oyor David Ifeanyichukwu

Department of Science Laboratory Technology, Akanu Ibiam Federal Polytechnic, Afikpo, Nigeria
Ogwo Jemima Ngozi

Department of Physics, Abia State University, Uturu, Nigeria

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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

Copy | Download

@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}
}

Copy | Download

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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