RADIO-LOUD ACTIVE GALACTIC NUCLEI IN THE CONTEXT OF THE EIGENVECTOR 1 PARAMETER SPACE

摘要

We consider the properties of radio-loud (RL) active galactic nuclei in the context of the eigenvector 1 (E1) parameter space. RL sources show a restricted E1 parameter space occupation relative to the radio-quiet (RQ) majority. The Fanaroff-Riley Ⅱ "parent population" of relatively unboosted RL sources (median radio/optical flux ratio ～490) shows the most restricted occupation. RL sources have different broad-line properties (and inferred black hole masses and Eddington ratios). FWHM Hβ for the broad-line component in RL sources are at least twice as large as in the RQ majority. The average broad Fe Ⅱ λ4570 emission-line strength is also about half that for RQ sources. Our sample suggests that the RL cutoff occurs near R_K ≈ 70 or log P_(6 cm) ～ 32.0 ergs s~(-1) Hz~(-1). Sources below this cutoff are RQ, although we cannot rule out the existence of a distinct intermediate population. We show that the Doppler-boosted core-dominated RL sources (median flux ratio ～1000) lie toward smaller FWHM(Hβ_(BC)) and stronger Fe Ⅱ_(opt) in E1, as expected if the lines arise in an accretion disk. Our subsample of superluminal sources, with orientation inferred from the synchrotron self-Compton model, reinforce this general E1 trend and allow us to estimate the role of source orientation in driving E1 domain occupation.