3C 57 as an atypical radio-loud quasar: implications for the radio-loudradio-quiet dichotomy

Sulentic, Jack W. ; Martínez Carballo, M. A. ; Marziani, P. ; Olmo, Ascensión del ; Stirpe, G.M. ; Zamfir, S. ; Plauchu-Frayn, I.

Resumen: 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 λ1549 profile blueshift (~-1500 km s^-1). 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 λ1549.

Idioma: Inglés

DOI: 10.1093/mnras/stv710

Año: 2015

Publicado en: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 450, 2 (2015), 1916-1925
ISSN: 0035-8711

Factor impacto JCR: 4.952 (2015)

Categ. JCR: ASTRONOMY & ASTROPHYSICS rank: 13 / 62 = 0.21 (2015) - Q1 - T1

Factor impacto SCIMAGO: 2.701 - Space and Planetary Science (Q1) - Astronomy and Astrophysics (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MICINN/AYA2010-15169
Financiación: info:eu-repo/grantAgreement/ES/MICINN/AYA2011-1544-E
Financiación: info:eu-repo/grantAgreement/ES/MICINN/AYA2013-42227-P

Tipo y forma: Artículo (Versión definitiva)