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On the Extend of Eddington Ratio and Accretion Rate in Seyfert 1 and Hidden Broad Line Region Seyfert 2 Galaxies

Received: 11 December 2021     Accepted: 11 January 2022     Published: 20 January 2022
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Abstract

We present our result on the Eddington ratios and accretion rates of 13,516 Seyfert galaxies consisting of 6,758 Seyfert 1s and 6,758 Seyfert 2s. These objects under study are a sub-sample of 91,006 Seyfert galaxies from SDSS-DR14. Using the separation criterion > 3 for Seyfert 2 galaxies, the 91,006 objects are separated into Seyferts 1s and 2s and we further select Hidden broadline region (HBLR) Seyfert 2s. Our results show that Seyfert 1 galaxies have higher Eddington ratio that Seyfert 2s an indication that Seyfert 1 galaxies may be more AGN-dominated than Seyfert 2 galaxies. We find the mean luminosity of the doubly ionized oxygen line () to be higher in Seyfert 2 galaxies a pointer that narrow line regions (NLRs) in Seyfert 2s may contain higher density of cloud of particles than Seyfert 1s. In addition, () is found to increase with increasing Eddington ratio which shows that the NLR is likely to be illuminated by the central region; a precursor that the central region and the NRL should be few parsecs apart. The observation we make that Seyferts 1 and 2 of equal black hole mass (=) have diametrically unequal Eddington ratio of log=8.9638 for Seyfert 2s and log=5.801 for Seyfert 1s suggests that each of the Seyfert classes may have been associated with different AGN activities. On accretion rate, Seyfert 2 galaxies have higher accretion rate which implies that they are probably in the gravitational force era dominated by absorption by matter while Seyfert 1s are probably in the radiation force dominated era and as such not associated with absorption by matter.

Published in International Journal of Astrophysics and Space Science (Volume 9, Issue 4)
DOI 10.11648/j.ijass.20210904.11
Page(s) 51-57
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), 2022. Published by Science Publishing Group

Keywords

Galaxies, Eddington Ratio, Accretion, Narrow Line Region, Brood Line Region

References
[1] Antonucci, R. R. J., &, J. S 1985, Spectropolarimetry and the Nature of NGC 1068 APJ, 297, 621.
[2] Bassani. L., Dadina, M., Maiolino, R., Salvati, M., Risaliti, G., Della Ceca, R., Matt, G., & Zamorani, G. 1999. A Three-Dimensional Diagnostic Diagram for Seyfert 2 galaxies: Probing X-ray Absorption and Compton Thickness, APJS, 121, 473.
[3] Bian, W., Gu, Q., Zhao, Y., Chao, L., & Cui, Q. 2006, Stellar and Gaseous Velocity Dispersions MNRAS, 372, 876 in Type II AGN at 0.3 < z < 0.83 from the Sloan Digital Sky Survey.
[4] Bian, W., 2004, The Black hole- Bulge Relation in Active Galactic Nuclei, MNRAS, 347, 607.
[5] Elitzur, M., & Shlosman, I. 2006, The AGN-obscuring Torus: the end of the Doughnut Paradigm. ApJ, 648, L101.
[6] Elitzur, M., Ho, L. C., &Trump, J. R. 2014, Evolution of Broad line Emission from Active Galactic Nuclei. MNRAS, 438, 3340.
[7] Heisler, C. A., Lumsden, S. L., & Bailey, J. A. 1997, Visibility of Scattered Broad-line Emission in Seyfert 2 galaxies, Nature, 385, 700.
[8] Heckman, T. M., Kauffmann, G., Brinchmann, J., Charlot, S. Tremonti, C., & White, S. D. M. 2004, The Growth of Present-day Black hole and Bulges: The Sloan Digital Sky Survey Perspective APJ, 613, 109.
[9] Koulouridis, E., Plionis, M., Chavushyan, V et al. 2013, Activities of the Seyfert galaxy Neighbors A & A, 552, A135.
[10] Laor, A. 2003. On the Nature of Low-luminosity Narrow-line Active Galactic Nuclei APJ, 590, 86.
[11] Lumsden, S. L., & Alexander, D. M. 2001, The Infrared Luminosity of the Torus and the Visibility of the Scatted Broad Line in Seyfert 2 Galaxies, MNRAS, 328, L32.
[12] Marinucci, A., Bianchi, S., Nicastro, F., Matt, G., & Goulding, A. D. 2012, The Link between the Hidden Line Region and the Accretion Rate in Seyfert 2 Galaxies. APJ, 748, 130.
[13] Maiolino, R., Salvati, M., Bassani, L., Dadina, M., Della Cecca, R., Matt, G., Risaliti, G., & Zamorani, G. 1998, Heavy Obscuration in X-ray Weak AGNs A&A, 338, 781.
[14] Nicastro, F. 2000, Broad Emission Line Regions in Active Galactic Nuclei: The Link with the Accretion Power APJ, 530, L65.
[15] Nicastro, F., Martocchia, A., & Matt, G. 2003, The Lack of Broad line Regions in Low Accretion Rate Active Galactic Nuclei as evidence of their Origing in the Accretion Disk, APJ, 589, L13.
[16] Panessa, F., & Bassani, L. 2002, Unabsorbed Seyfert 2 Galaxies A&A, 394, 435.
[17] Risaliti, G., Maiolino, R., & Salvati, M. 1999. The Distribution of Absorbing Column Densities among Seyfert 2 Galaxies APJ, 622, 157.
[18] Trans, H. D. 1995, The Nature of Seyfert 2 Galaxies with Obscured Broad Line Region. I. Observation APJ. 440, 565.
[19] Trans, H. D, 2001, Dusty Nuclear Disks and Filaments in early-type Galaxies APJ, 554, L19.
[20] Vander Wolk, G., Barthel, P. D., Peletier, R. F., & Pel, J. W 2010, A&A 552, A135.
[21] Veilleux, S., Goodrich, R. W., & Hill, G. J. 1997, Infrared Spectroscopy of Seyfert 2 Galaxies: A look through the Obscuring Torus. II. APJ, 477, 631.
[22] Moran, E. C., Barth, A. J., Kay, L. E., & Filippenko, A. V. 2000, The Frequency of Polarized Broad Emission Lines in Seyfert Galaxies APJ, 540, L73.
[23] Whysong, D., & Antonucci, R. 2004, Thermal Emission as a Test for Hidden Nuclei in Near-by Seyfert Galaxies APJ, 602, 116.
[24] Zakamska, N. L., 2005, Candidate Type II Quasars from the Sloan Digital Sky Survey III Spectropolametry Reveals Hidden Type I Nuclei APJ, 129, 1212.
Cite This Article
  • APA Style

    Nwankwo Ifeanyi Francis, Ogwo Jemima Ngozi. (2022). On the Extend of Eddington Ratio and Accretion Rate in Seyfert 1 and Hidden Broad Line Region Seyfert 2 Galaxies. International Journal of Astrophysics and Space Science, 9(4), 51-57. https://doi.org/10.11648/j.ijass.20210904.11

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    ACS Style

    Nwankwo Ifeanyi Francis; Ogwo Jemima Ngozi. On the Extend of Eddington Ratio and Accretion Rate in Seyfert 1 and Hidden Broad Line Region Seyfert 2 Galaxies. Int. J. Astrophys. Space Sci. 2022, 9(4), 51-57. doi: 10.11648/j.ijass.20210904.11

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    AMA Style

    Nwankwo Ifeanyi Francis, Ogwo Jemima Ngozi. On the Extend of Eddington Ratio and Accretion Rate in Seyfert 1 and Hidden Broad Line Region Seyfert 2 Galaxies. Int J Astrophys Space Sci. 2022;9(4):51-57. doi: 10.11648/j.ijass.20210904.11

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  • @article{10.11648/j.ijass.20210904.11,
      author = {Nwankwo Ifeanyi Francis and Ogwo Jemima Ngozi},
      title = {On the Extend of Eddington Ratio and Accretion Rate in Seyfert 1 and Hidden Broad Line Region Seyfert 2 Galaxies},
      journal = {International Journal of Astrophysics and Space Science},
      volume = {9},
      number = {4},
      pages = {51-57},
      doi = {10.11648/j.ijass.20210904.11},
      url = {https://doi.org/10.11648/j.ijass.20210904.11},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijass.20210904.11},
      abstract = {We present our result on the Eddington ratios and accretion rates of 13,516 Seyfert galaxies consisting of 6,758 Seyfert 1s and 6,758 Seyfert 2s. These objects under study are a sub-sample of 91,006 Seyfert galaxies from SDSS-DR14. Using the separation criterion > 3 for Seyfert 2 galaxies, the 91,006 objects are separated into Seyferts 1s and 2s and we further select Hidden broadline region (HBLR) Seyfert 2s. Our results show that Seyfert 1 galaxies have higher Eddington ratio that Seyfert 2s an indication that Seyfert 1 galaxies may be more AGN-dominated than Seyfert 2 galaxies. We find the mean luminosity of the doubly ionized oxygen line () to be higher in Seyfert 2 galaxies a pointer that narrow line regions (NLRs) in Seyfert 2s may contain higher density of cloud of particles than Seyfert 1s. In addition, () is found to increase with increasing Eddington ratio which shows that the NLR is likely to be illuminated by the central region; a precursor that the central region and the NRL should be few parsecs apart. The observation we make that Seyferts 1 and 2 of equal black hole mass (=) have diametrically unequal Eddington ratio of log=8.9638 for Seyfert 2s and log=5.801 for Seyfert 1s suggests that each of the Seyfert classes may have been associated with different AGN activities. On accretion rate, Seyfert 2 galaxies have higher accretion rate which implies that they are probably in the gravitational force era dominated by absorption by matter while Seyfert 1s are probably in the radiation force dominated era and as such not associated with absorption by matter.},
     year = {2022}
    }
    

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  • TY  - JOUR
    T1  - On the Extend of Eddington Ratio and Accretion Rate in Seyfert 1 and Hidden Broad Line Region Seyfert 2 Galaxies
    AU  - Nwankwo Ifeanyi Francis
    AU  - Ogwo Jemima Ngozi
    Y1  - 2022/01/20
    PY  - 2022
    N1  - https://doi.org/10.11648/j.ijass.20210904.11
    DO  - 10.11648/j.ijass.20210904.11
    T2  - International Journal of Astrophysics and Space Science
    JF  - International Journal of Astrophysics and Space Science
    JO  - International Journal of Astrophysics and Space Science
    SP  - 51
    EP  - 57
    PB  - Science Publishing Group
    SN  - 2376-7022
    UR  - https://doi.org/10.11648/j.ijass.20210904.11
    AB  - We present our result on the Eddington ratios and accretion rates of 13,516 Seyfert galaxies consisting of 6,758 Seyfert 1s and 6,758 Seyfert 2s. These objects under study are a sub-sample of 91,006 Seyfert galaxies from SDSS-DR14. Using the separation criterion > 3 for Seyfert 2 galaxies, the 91,006 objects are separated into Seyferts 1s and 2s and we further select Hidden broadline region (HBLR) Seyfert 2s. Our results show that Seyfert 1 galaxies have higher Eddington ratio that Seyfert 2s an indication that Seyfert 1 galaxies may be more AGN-dominated than Seyfert 2 galaxies. We find the mean luminosity of the doubly ionized oxygen line () to be higher in Seyfert 2 galaxies a pointer that narrow line regions (NLRs) in Seyfert 2s may contain higher density of cloud of particles than Seyfert 1s. In addition, () is found to increase with increasing Eddington ratio which shows that the NLR is likely to be illuminated by the central region; a precursor that the central region and the NRL should be few parsecs apart. The observation we make that Seyferts 1 and 2 of equal black hole mass (=) have diametrically unequal Eddington ratio of log=8.9638 for Seyfert 2s and log=5.801 for Seyfert 1s suggests that each of the Seyfert classes may have been associated with different AGN activities. On accretion rate, Seyfert 2 galaxies have higher accretion rate which implies that they are probably in the gravitational force era dominated by absorption by matter while Seyfert 1s are probably in the radiation force dominated era and as such not associated with absorption by matter.
    VL  - 9
    IS  - 4
    ER  - 

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

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

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