95451 20240122154814.0 doi 10.1093/mnras/stv710 sideral 109953 ART-2015-109953 eng Sulentic, Jack W. 3C 57 as an atypical radio-loud quasar: implications for the radio-loudradio-quiet dichotomy 2015 Access copy available to the general public Unrestricted Lobe-dominated radio-loud (LD RL) quasars occupy a restricted domain in the 4D Eigenvector 1 (4DE1) parameter space which implies restricted geometry/physics/kinematics for this subclass compared to the radio-quiet (RQ) majority of quasars. We discuss how this restricted domain for the LD RL parent population supports the notion for a RQ-RL dichotomy among type 1 sources. 3C 57 is an atypical RL quasar that shows both uncertain radio morphology and falls in a region of 4DE1 space where RL quasars are rare. We present new radio flux and optical spectroscopic measures designed to verify its atypical optical/UV spectroscopic behaviour and clarify its radio structure. The former data confirms that 3C 57 falls off the 4DE1 quasar ''main sequence'' with both extreme optical Fe II emission (RFe II ~ 1) and a large CIV Œª1549 profile blueshift (~-1500 km s<sup>-1</sup>). These parameter values are typical of extreme Population A sources which are almost always RQ. New radio measures show no evidence for flux change over a 50+year time-scale consistent with compact steep-spectrum (or young LD) over core-dominated morphology. In the 4DE1 context where LD RL are usually low L/L<inf>Edd</inf> quasars, we suggest that 3C 57 is an evolved RL quasar (i.e. large blackhole mass) undergoing a major accretion event leading to a rejuvenation reflected by strong Fe II emission, perhaps indicating significant heavy metal enrichment, high bolometric luminosity for a low-redshift source and resultant unusually high Eddington ratio giving rise to the atypical CIV Œª1549. info:eu-repo/grantAgreement/ES/MICINN/AYA2010-15169 info:eu-repo/grantAgreement/ES/MICINN/AYA2011-1544-E info:eu-repo/grantAgreement/ES/MICINN/AYA2013-42227-P info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 4.952 2015 ASTRONOMY & ASTROPHYSICS 13 / 62 = 0.21 2015 Q1 T1 2.701 2015 Space and Planetary Science 2015 Q1 Astronomy and Astrophysics 2015 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Martínez Carballo, M. A. (orcid)0000-0002-7374-3222 Marziani, P. Olmo, Ascensión del Stirpe, G.M. Zamfir, S. Plauchu-Frayn, I. 450, 2 (2015), 1916-1925 Mon. not. R. Astron. Soc. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 0035-8711 436114 http://zaguan.unizar.es/record/95451/files/texto_completo.pdf Versión publicada 476638 http://zaguan.unizar.es/record/95451/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:95451 articulos driver 2024-01-22-15:32:44 ARTICLE