The nature of active galaxies based on their radio properties

Abstract

In this paper, we investigate radio properties of active galaxies taken from the reference [Véron‐Cetty & Véron (2010)] catalog. The galaxies are limited to magnitudes in the range of 12m − 19m. We have cross‐correlated the list with radio catalogs and selected those galaxies that have data on six or more radio fluxes at different wavelengths. As a result, we have 198 galaxies that satisfy these conditions. Using SDSS DR15, we have obtained 96 spectroscopic identifications of the 198 objects. After the classification, 85% of the 96 objects have changed their types. Available data on the classification of these objects and our classification showed that 56.7% of them are Seyfert galaxies. For all the objects, we have built radio spectra and estimated radio spectral indices. As a result, we obtain αtrue‾=−0.6089±0.056(trueα‾Seyfert=−0.6013±0.027, trueα‾LINER=−0.5955±0.025, trueα‾normalHII=−0.6672±0.039, trueα‾Comp.=−0.7128±0.043). We discuss the radio properties of active galaxies based on their radio spectral indices.

Study of the radio and optical properties of Active Galactic Nuclei

“…For more confident classification we used three diagnostic diagrams and direct study of the spectra. As a result, we have changed classification for 85% of these objects (Abrahamyan (2020) and Abrahamyan et al (2020)).…”

“…This catalog includes 133,336 quasars, 1,374 BL Lac objects, and 34,231 active galaxies (including 16,517 Seyfert 1.0). We have considered 34,231 active galaxies for our research (Abrahamyan (2020) and Abrahamyan et al (2020)).…”

Fine classification of the emission-line spectra of active galaxies

“…In a number of our papers, we have used unified approach to classify thousands of spectra for active galaxies from various samples (Abrahamyan, 2020, Abrahamyan et al, 2018b, 2019a, 2020, Mickaelian et al, 2018, 2020. Our approach is based on BPT diagrams (Baldwin et al, 1981, Veilleux & Osterbrock, 1987, however we use most recent options of such diagrams (Kewley et al, 2006, Reines et al, 2013.…”

“…In this paper we give this classification scheme and describe all possible classes and subclasses based on their emission-line features, both main emission lines (H, NII, OIII, OI, SII) and other minor details. Our scheme is based on our research carried out during the last 10-15 years (HyperLEDA (2007), Mickaelian (2015), Mickaelian et al (2007Mickaelian et al ( , 2011Mickaelian et al ( , 2018Mickaelian et al ( , 2021, Gavrilović et al (2007), Abrahamyan (2020), Abrahamyan et al (2018aAbrahamyan et al ( ,b, 2019aAbrahamyan et al ( ,b, 2020, Paronyan et al (2019Paronyan et al ( , 2020, Mikayelyan et al (2019), and many others.) and has a strong observational basis.…”

Analysis of emission line spectra of active galaxies and fine classification for activity types

“…In this paper we give this classification scheme and describe all possible classes and subclasses based on their emission-line features, both main emission lines (H, NII, OIII, OI, SII) and other minor details. Our scheme is based on our research carried out during the last 10-15 years (HyperLEDA (2007), Mickaelian (2015), Mickaelian et al (2007Mickaelian et al ( , 2011Mickaelian et al ( , 2018Mickaelian et al ( , 2021, Gavrilovic et al (2007), Abrahamyan (2020) 2019a,b, 2020)), Paronyan et al (2019Paronyan et al ( , 2020, Mikayelyan et al (2019), and many others.) and has a strong observational basis.…”