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.
Publisher
The Korean Space Science Society
Subject
General Earth and Planetary Sciences,General Physics and Astronomy
Reference39 articles.
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).
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).
3. Antonucci R, Unified models for active galactic nuclei and
quasars, Annu. Rev. Astron. Astrophys. 31, 473-521 (1993).
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). 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). 10.1088/0004-637X/759/1/30