NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-18 T13:09:43 PDT
Help | Comment | NED Home

For refcode 2012MNRAS.426.2703S:
Retrieve 3410 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by Royal Astronomical Society. 2012MNRAS.426.2703S Type 1 AGN at low z - II. The relative strength of narrow lines and the nature of intermediate type AGN Stern, Jonathan; Laor, Ari Abstract. We explore the relative strength of the narrow emission lines in a Sloan Digital Sky Survey based sample of broad Halpha selected active galactic nuclei (AGN), defined in Paper I. We find a decrease in the narrow to broad Halpha luminosity (L_bHalpha_) ratio with increasing L_bHalpha_, such that both L([O III ] lambda5007) and L(narrow Halpha) scale as is proportional to L bH {alpha}0.7 for 1040<L bH {alpha}<1045 erg s-1. Following our earlier result that L_bHalpha_ is proportional to L_bol_, this trend indicates that the relative narrow line luminosity decreases with increasing L_bol_. We derive L bol /1043 erg s-1=4000(L([O III ])/1043 erg s-1)1.39. This implies that the bolometric correction factor, L bol /L([O III ]), decreases from 3000 at L bol =1046.1 erg s-1 to 300 at L bol =1042.5 erg s-1. At low luminosity, the narrow component dominates the observed Halpha profile, and most type 1 AGN appear as intermediate type AGN. Partial obscuration or extinction cannot explain the dominance of intermediate type AGN at low luminosity, and the most likely mechanism is a decrease in the narrow line region covering factor with increasing L_bol_. Deviations from the above trend occur in objects with L/L_Edd_ <~ 10^-2.6^, probably due to the transition to LINERs with suppressed [O III] emission, and in objects with M_BH_ > 10^8.5^ M_sun_, probably due to the dominance of radio-loud AGN, and associated enhanced [O III] emission. Key words: galaxies: Seyfert
Retrieve 3410 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home