Investigating possible unification of Seyfert galaxies and blazars in Fermi‐Large Area Telescope sample

• Published in: Astronomische Nachrichten Vol. 342; no. 7-8; pp. 1024 - 1033
• Main Authors: Iyida, Evaristus U., Eya, Innocent O., Odo, Finbarr C.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH & Co. KGaA 01.08.2021; Wiley Subscription Services, Inc
• Subjects: BL Lacertae objects; Blazars; Emission analysis; Extragalactic radio sources; Galactic evolution; galaxies: active – BL Lacertae objects: general – Seyfert galaxies: FSRQs; Luminosity; Quasars; Seyfert galaxies; Statistical analysis
• ISSN: 0004-6337; 1521-3994
• DOI: 10.1002/asna.20210005

Statistical analyses are invaluable methods used to understand intrinsic emission processes and the unification of extragalactic radio sources. In this paper, we collected radio, X‐ray, and γ‐ray data of blazars from the Fermi Large Area Telescope (Fermi‐LAT) and Seyfert galaxies from the INTEGRAL/IBIS survey and investigated the relationship between the emission properties of Seyfert galaxies and blazar subclasses of flat‐spectrum radio quasars (FSRQs) and BL Lac objects (BL Lacs). The results show from the average values that these objects follow a sequence that is indicative of probable Seyfert galaxies‐BL Lacs‐FSRQs unification. We discovered that Seyfert galaxies, BL Lacs, and FSRQs share similar emission characteristics in X‐ray luminosity (LX‐ray), suggestive of fundamental connection while the γ‐ray (Lγ‐ray) and radio (Lradio) luminosities of Seyfert galaxies are the least powerful, signifying an evolving structure. From the two‐dimensional Kolmogorov–Smirnov (K−S) test, we found that Seyfert galaxies differ from the blazar subclasses in Lradio while there is no significant difference between them in LX‐ray and Lγ‐ray which implies that high‐energy emissions in Seyfert galaxies and blazar subclasses may come from the same emission mechanism. Significant positive correlations (with coefficient r > 0.60) exist between the high‐energy luminosities (X‐ray and γ‐ray) and the low‐energy components (radio) within the whole sample of blazars and Seyfert galaxies implying a form of connection between them. These results are not only consistent with the prediction of the unified scheme for blazars but also show that Seyfert galaxies have an evolutionary link with blazar subclasses.